diff --git a/README.md b/README.md
index 9477740..e602b0f 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,16 @@
 # ac-nh-turnip-prices
 Price calculator/predictor for Turnip prices
+
+## Scope
+
+This tool is:
+- A predictor for future prices that week
+- Able to calculate probabilities for different futures
+- Able to show data from a query string
+- A single page web-based app
+
+This tool is not:
+- A calculator for how much money you'll make
+- A way to count your turnips
+- A way to store multiple people's islands
+- Something with a backend
diff --git a/css/styles.css b/css/styles.css
index ff3e08d..ee7d60c 100644
--- a/css/styles.css
+++ b/css/styles.css
@@ -368,7 +368,15 @@ input[type=number] {
   white-space: nowrap;
 }
 
-
+.chart-wrapper {
+  margin-top: 8px;
+  display: flex;
+  flex-wrap: wrap;
+  height: 400px;
+  width: 100%;
+  max-width: 1080px;
+  justify-content: center;
+}
 
 
 .waves {
diff --git a/img/192.png b/img/192.png
new file mode 100644
index 0000000..68b4ae5
Binary files /dev/null and b/img/192.png differ
diff --git a/img/512.png b/img/512.png
new file mode 100644
index 0000000..a59c3ec
Binary files /dev/null and b/img/512.png differ
diff --git a/index.html b/index.html
index 0a106be..e1adac5 100644
--- a/index.html
+++ b/index.html
@@ -8,7 +8,10 @@
   <title>Animal Crossing - Turnip Prophet</title>
   <meta name="description" content="Animal Crossing - Turnip Prophet">
   <meta name="author" content="Mike Bryant">
+  <meta name="theme-color" content="#def2d9">
 
+  <link rel="manifest" href="/manifest.json">
+  <link rel="apple-touch-icon" href="/img/192.png">
   <link rel="stylesheet" href="css/styles.css">
 
   <!-- Global site tag (gtag.js) - Google Analytics -->
@@ -98,13 +101,12 @@
         <div class="form__row">
           <h6>Sunday</h6>
           <div class="input__group">
-            <label>What was the price of turnips this week? <i>(If this is your first time buying turnips, this field
+            <label>What was the price of turnips this week on your island? <i>(If this is your first time buying turnips, this field
                 will be disabled)</i></label>
             <input type="number" id="buy" placeholder="..." />
 
           </div>
         </div>
-
         <i>AM - 8:00 am to 11:59 am</i>
         <i>PM - 12:00 pm to 10:00 pm</i>
         <div class="form__flex-wrap">
@@ -189,6 +191,10 @@
 
       <h2>Output</h2>
 
+      <div class="chart-wrapper">
+        <canvas id="chart" width="100%" height="100"></canvas>
+      </div>
+
       <div class="table-wrapper">
         <table id="turnipTable">
           <thead>
@@ -263,6 +269,7 @@
         </g>
       </svg>
     </div>
+  </div>
 
   </div>
 
@@ -284,13 +291,42 @@
       Support, comments and contributions are available through <a
         href="https://github.com/mikebryant/ac-nh-turnip-prices/issues">Github</a>
     </p>
+    <p>Oh! And let's not forget to thank those who have contributed so far!</p>
+    <p id="contributors">
+      Contributors:
+    </p>
   </div>
 
   <script src="https://code.jquery.com/jquery-3.4.1.min.js"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
+  <script src="js/chart.js"></script>
   <script src="js/predictions.js"></script>
   <script src="js/scripts.js"></script>
   <script src="https://cdn.jsdelivr.net/npm/darkmode-js@1.5.5/lib/darkmode-js.min.js"></script>
   <script> new Darkmode({label: '🌓', buttonColorDark: '#fff00'}).showWidget();</script>
+  <script src="js/contributors.js"></script>
+  <script>
+    // Check compatibility for the browser we're running this in
+    if ("serviceWorker" in navigator) {
+      if (navigator.serviceWorker.controller) {
+        console.log(
+          "[PWA] Service Worker already found, skipping register"
+        );
+      } else {
+        // Register the service worker
+        navigator.serviceWorker
+          .register("/service-worker.js", {
+            scope: "./",
+          })
+          .then(function (reg) {
+            console.log(
+              "[PWA] Service worker has been registered for scope: " +
+                reg.scope
+            );
+          });
+      }
+    }
+  </script>
 </body>
 
 </html>
diff --git a/js/chart.js b/js/chart.js
new file mode 100644
index 0000000..9ea48c5
--- /dev/null
+++ b/js/chart.js
@@ -0,0 +1,54 @@
+let chart_instance = null;
+
+Chart.defaults.global.defaultFontFamily = "'Varela Round', sans-serif";
+
+const chart_options = {
+  elements: {
+    line: {
+      backgroundColor: "#DEF2D9",
+      backgroundColor: "#DEF2D9",
+      cubicInterpolationMode: "monotone",
+    },
+  },
+  maintainAspectRatio: false,
+  tooltips: {
+    intersect: false,
+    mode: "index",
+  },
+};
+
+function update_chart(input_data, possibilities) {
+  var ctx = $("#chart");
+
+  datasets = [
+    {
+      label: "Input Price",
+      data: input_data.slice(1),
+      fill: false,
+    },
+    {
+      label: "Minimum",
+      data: possibilities[0].prices.slice(1).map(day => day.min),
+      fill: false,
+    },
+    {
+      label: "Maximum",
+      data: possibilities[0].prices.slice(1).map(day => day.max),
+      fill: "-1",
+    },
+  ];
+
+  if (chart_instance) {
+    chart_instance.data.datasets = datasets;
+    chart_instance.update();
+  } else {
+    chart_instance = new Chart(ctx, {
+      data: {
+        datasets: datasets,
+        labels: ["Sunday", "Mon AM", "Mon PM", "Tue AM", "Tue PM", "Wed AM", "Wed PM", "Thu AM", "Thu PM", "Fri AM", "Fri PM", "Sat AM", "Sat PM"],
+      },
+      options: chart_options,
+      type: "line",
+    });
+  }
+}
diff --git a/js/contributors.js b/js/contributors.js
new file mode 100644
index 0000000..e3cf7eb
--- /dev/null
+++ b/js/contributors.js
@@ -0,0 +1,16 @@
+function getContributors() {
+  if (window.jQuery) {
+    const container = $('#contributors');
+    jQuery.ajax('https://api.github.com/repos/mikebryant/ac-nh-turnip-prices/contributors', {})
+      .done(function (data) {
+        data.forEach((contributor, idx) => {
+          container.append(`<a href="${contributor.html_url}">${contributor.login}</a>`);
+          if (idx < data.length - 1) {
+            container.append(', ');
+          }
+        });
+      });
+  }
+}
+
+$(document).ready(getContributors);
diff --git a/js/predictions.js b/js/predictions.js
index 96fe462..f1410a6 100644
--- a/js/predictions.js
+++ b/js/predictions.js
@@ -1,3 +1,7 @@
+// The reverse-engineered code is not perfectly accurate, especially as it's not
+// 32-bit ARM floating point. So, be tolerant of slightly unexpected inputs
+const FUDGE_FACTOR = 5;
+
 const PATTERN = {
   FLUCTUATING: 0,
   LARGE_SPIKE: 1,
@@ -10,7 +14,7 @@ const PATTERN_COUNTS = {
   [PATTERN.LARGE_SPIKE]: 7,
   [PATTERN.DECREASING]: 1,
   [PATTERN.SMALL_SPIKE]: 8,
-}
+};
 
 const PROBABILITY_MATRIX = {
   [PATTERN.FLUCTUATING]: {
@@ -39,15 +43,187 @@ const PROBABILITY_MATRIX = {
   },
 };
 
+const RATE_MULTIPLIER = 10000;
+
+function intceil(val) {
+  return Math.trunc(val + 0.99999);
+}
+
 function minimum_rate_from_given_and_base(given_price, buy_price) {
-  return 10000 * (given_price - 1) / buy_price;
+  return RATE_MULTIPLIER * (given_price - 0.99999) / buy_price;
 }
 
 function maximum_rate_from_given_and_base(given_price, buy_price) {
-  return 10000 * given_price / buy_price;
+  return RATE_MULTIPLIER * (given_price + 0.00001) / buy_price;
+}
+
+function get_price(rate, basePrice) {
+  return intceil(rate * basePrice / RATE_MULTIPLIER);
+}
+
+/*
+ * This corresponds to the code:
+ *   for (int i = start; i < start + length; i++)
+ *   {
+ *     sellPrices[work++] =
+ *       intceil(randfloat(rate_min / RATE_MULTIPLIER, rate_max / RATE_MULTIPLIER) * basePrice);
+ *   }
+ *
+ * Would modify the predicted_prices array.
+ * If the given_prices won't match, returns false, otherwise returns true
+ */
+function generate_individual_random_price(
+    given_prices, predicted_prices, start, length, rate_min, rate_max) {
+  rate_min *= RATE_MULTIPLIER;
+  rate_max *= RATE_MULTIPLIER;
+
+  const buy_price = given_prices[0];
+
+  for (let i = start; i < start + length; i++) {
+    let min_pred = get_price(rate_min, buy_price);
+    let max_pred = get_price(rate_max, buy_price);
+    if (!isNaN(given_prices[i])) {
+      if (given_prices[i] < min_pred - FUDGE_FACTOR || given_prices[i] > max_pred + FUDGE_FACTOR) {
+        // Given price is out of predicted range, so this is the wrong pattern
+        return false;
+      }
+      min_pred = given_prices[i];
+      max_pred = given_prices[i];
+    }
+
+    predicted_prices.push({
+      min: min_pred,
+      max: max_pred,
+    });
+  }
+  return true;
+}
+
+/*
+ * This corresponds to the code:
+ *   rate = randfloat(start_rate_min, start_rate_max);
+ *   for (int i = start; i < start + length; i++)
+ *   {
+ *     sellPrices[work++] = intceil(rate * basePrice);
+ *     rate -= randfloat(rate_decay_min, rate_decay_max);
+ *   }
+ *
+ * Would modify the predicted_prices array.
+ * If the given_prices won't match, returns false, otherwise returns true
+ */
+function generate_decreasing_random_price(
+    given_prices, predicted_prices, start, length, rate_min,
+    rate_max, rate_decay_min, rate_decay_max) {
+  rate_min *= RATE_MULTIPLIER;
+  rate_max *= RATE_MULTIPLIER;
+  rate_decay_min *= RATE_MULTIPLIER;
+  rate_decay_max *= RATE_MULTIPLIER;
+
+  const buy_price = given_prices[0];
+
+  for (let i = start; i < start + length; i++) {
+    let min_pred = get_price(rate_min, buy_price);
+    let max_pred = get_price(rate_max, buy_price);
+    if (!isNaN(given_prices[i])) {
+      if (given_prices[i] < min_pred - FUDGE_FACTOR || given_prices[i] > max_pred + FUDGE_FACTOR) {
+        // Given price is out of predicted range, so this is the wrong pattern
+        return false;
+      }
+      if (given_prices[i] >= min_pred || given_prices[i] <= max_pred) {
+        // The value in the FUDGE_FACTOR range is ignored so the rate range would not be empty.
+        const real_rate_min = minimum_rate_from_given_and_base(given_prices[i], buy_price);
+        const real_rate_max = maximum_rate_from_given_and_base(given_prices[i], buy_price);
+        rate_min = Math.max(rate_min, real_rate_min);
+        rate_max = Math.min(rate_max, real_rate_max);
+      }
+      min_pred = given_prices[i];
+      max_pred = given_prices[i];
+    }
+
+    predicted_prices.push({
+      min: min_pred,
+      max: max_pred,
+    });
+
+    rate_min -= rate_decay_max;
+    rate_max -= rate_decay_min;
+  }
+  return true;
+}
+
+
+/*
+ * This corresponds to the code:
+ *   rate = randfloat(rate_min, rate_max);
+ *   sellPrices[work++] = intceil(randfloat(rate_min, rate) * basePrice) - 1;
+ *   sellPrices[work++] = intceil(rate * basePrice);
+ *   sellPrices[work++] = intceil(randfloat(rate_min, rate) * basePrice) - 1;
+ *
+ * Would modify the predicted_prices array.
+ * If the given_prices won't match, returns false, otherwise returns true
+ */
+function generate_peak_price(
+    given_prices, predicted_prices, start, rate_min, rate_max) {
+  rate_min *= RATE_MULTIPLIER;
+  rate_max *= RATE_MULTIPLIER;
+
+  const buy_price = given_prices[0];
+
+  // Main spike 1
+  min_pred = get_price(rate_min, buy_price) - 1;
+  max_pred = get_price(rate_max, buy_price) - 1;
+  if (!isNaN(given_prices[start])) {
+    if (given_prices[start] < min_pred - FUDGE_FACTOR || given_prices[start] > max_pred + FUDGE_FACTOR) {
+      // Given price is out of predicted range, so this is the wrong pattern
+      return false;
+    }
+    min_pred = given_prices[start];
+    max_pred = given_prices[start];
+  }
+  predicted_prices.push({
+    min: min_pred,
+    max: max_pred,
+  });
+
+  // Main spike 2
+  min_pred = predicted_prices[start].min;
+  max_pred = intceil(2.0 * buy_price);
+  if (!isNaN(given_prices[start + 1])) {
+    if (given_prices[start + 1] < min_pred - FUDGE_FACTOR || given_prices[start + 1] > max_pred + FUDGE_FACTOR) {
+      // Given price is out of predicted range, so this is the wrong pattern
+      return false;
+    }
+    min_pred = given_prices[start + 1];
+    max_pred = given_prices[start + 1];
+  }
+  predicted_prices.push({
+    min: min_pred,
+    max: max_pred,
+  });
+
+  // Main spike 3
+  min_pred = intceil(1.4 * buy_price) - 1;
+  max_pred = predicted_prices[start + 1].max - 1;
+  if (!isNaN(given_prices[start + 2])) {
+    if (given_prices[start + 2] < min_pred - FUDGE_FACTOR || given_prices[start + 2] > max_pred + FUDGE_FACTOR) {
+      // Given price is out of predicted range, so this is the wrong pattern
+      return false;
+    }
+    min_pred = given_prices[start + 2];
+    max_pred = given_prices[start + 2];
+  }
+  predicted_prices.push({
+    min: min_pred,
+    max: max_pred,
+  });
+
+  return true;
 }
 
-function* generate_pattern_0_with_lengths(given_prices, high_phase_1_len, dec_phase_1_len, high_phase_2_len, dec_phase_2_len, high_phase_3_len) {
+function*
+    generate_pattern_0_with_lengths(
+        given_prices, high_phase_1_len, dec_phase_1_len, high_phase_2_len,
+        dec_phase_2_len, high_phase_3_len) {
   /*
       // PATTERN 0: high, decreasing, high, decreasing, high
       work = 2;
@@ -84,8 +260,8 @@ function* generate_pattern_0_with_lengths(given_prices, high_phase_1_len, dec_ph
       }
   */
 
-  buy_price = given_prices[0];
-  var predicted_prices = [
+  const buy_price = given_prices[0];
+  const predicted_prices = [
     {
       min: buy_price,
       max: buy_price,
@@ -97,120 +273,45 @@ function* generate_pattern_0_with_lengths(given_prices, high_phase_1_len, dec_ph
   ];
 
   // High Phase 1
-  for (var i = 2; i < 2 + high_phase_1_len; i++) {
-    min_pred = Math.floor(0.9 * buy_price);
-    max_pred = Math.ceil(1.4 * buy_price);
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
+  if (!generate_individual_random_price(
+          given_prices, predicted_prices, 2, high_phase_1_len, 0.9, 1.4)) {
+    return;
   }
 
   // Dec Phase 1
-  var min_rate = 6000;
-  var max_rate = 8000;
-  for (var i = 2 + high_phase_1_len; i < 2 + high_phase_1_len + dec_phase_1_len; i++) {
-    min_pred = Math.floor(min_rate * buy_price / 10000);
-    max_pred = Math.ceil(max_rate * buy_price / 10000);
-
-
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-      min_rate = minimum_rate_from_given_and_base(given_prices[i], buy_price);
-      max_rate = maximum_rate_from_given_and_base(given_prices[i], buy_price);
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
-
-    min_rate -= 1000;
-    max_rate -= 400;
+  if (!generate_decreasing_random_price(
+          given_prices, predicted_prices, 2 + high_phase_1_len, dec_phase_1_len,
+          0.6, 0.8, 0.04, 0.1)) {
+    return;
   }
 
   // High Phase 2
-  for (var i = 2 + high_phase_1_len + dec_phase_1_len; i < 2 + high_phase_1_len + dec_phase_1_len + high_phase_2_len; i++) {
-    min_pred = Math.floor(0.9 * buy_price);
-    max_pred = Math.ceil(1.4 * buy_price);
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
+  if (!generate_individual_random_price(given_prices, predicted_prices,
+      2 + high_phase_1_len + dec_phase_1_len, high_phase_2_len, 0.9, 1.4)) {
+    return;
   }
 
   // Dec Phase 2
-  var min_rate = 6000;
-  var max_rate = 8000;
-  for (var i = 2 + high_phase_1_len + dec_phase_1_len + high_phase_2_len; i < 2 + high_phase_1_len + dec_phase_1_len + high_phase_2_len + dec_phase_2_len; i++) {
-    min_pred = Math.floor(min_rate * buy_price / 10000);
-    max_pred = Math.ceil(max_rate * buy_price / 10000);
-
-
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-      min_rate = minimum_rate_from_given_and_base(given_prices[i], buy_price);
-      max_rate = maximum_rate_from_given_and_base(given_prices[i], buy_price);
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
-
-    min_rate -= 1000;
-    max_rate -= 400;
+  if (!generate_decreasing_random_price(
+          given_prices, predicted_prices,
+          2 + high_phase_1_len + dec_phase_1_len + high_phase_2_len,
+          dec_phase_2_len, 0.6, 0.8, 0.04, 0.1)) {
+    return;
   }
 
   // High Phase 3
   if (2 + high_phase_1_len + dec_phase_1_len + high_phase_2_len + dec_phase_2_len + high_phase_3_len != 14) {
     throw new Error("Phase lengths don't add up");
   }
-  for (var i = 2 + high_phase_1_len + dec_phase_1_len + high_phase_2_len + dec_phase_2_len; i < 14; i++) {
-    min_pred = Math.floor(0.9 * buy_price);
-    max_pred = Math.ceil(1.4 * buy_price);
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-    }
 
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
+  const prev_length = 2 + high_phase_1_len + dec_phase_1_len +
+      high_phase_2_len + dec_phase_2_len;
+  if (!generate_individual_random_price(
+          given_prices, predicted_prices, prev_length, 14 - prev_length, 0.9,
+          1.4)) {
+    return;
   }
+
   yield {
     pattern_description: "Fluctuating",
     pattern_number: 0,
@@ -257,8 +358,8 @@ function* generate_pattern_1_with_peak(given_prices, peak_start) {
     }
   */
 
-  buy_price = given_prices[0];
-  var predicted_prices = [
+  const buy_price = given_prices[0];
+  const predicted_prices = [
     {
       min: buy_price,
       max: buy_price,
@@ -269,54 +370,21 @@ function* generate_pattern_1_with_peak(given_prices, peak_start) {
     },
   ];
 
-  var min_rate = 8500;
-  var max_rate = 9000;
-
-  for (var i = 2; i < peak_start; i++) {
-    min_pred = Math.floor(min_rate * buy_price / 10000);
-    max_pred = Math.ceil(max_rate * buy_price / 10000);
-
-
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-      min_rate = minimum_rate_from_given_and_base(given_prices[i], buy_price);
-      max_rate = maximum_rate_from_given_and_base(given_prices[i], buy_price);
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
-
-    min_rate -= 500;
-    max_rate -= 300;
+  if (!generate_decreasing_random_price(
+          given_prices, predicted_prices, 2, peak_start - 2, 0.85, 0.9, 0.03,
+          0.05)) {
+    return;
   }
 
   // Now each day is independent of next
   min_randoms = [0.9, 1.4, 2.0, 1.4, 0.9, 0.4, 0.4, 0.4, 0.4, 0.4, 0.4]
   max_randoms = [1.4, 2.0, 6.0, 2.0, 1.4, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9]
-  for (var i = peak_start; i < 14; i++) {
-    min_pred = Math.floor(min_randoms[i - peak_start] * buy_price);
-    max_pred = Math.ceil(max_randoms[i - peak_start] * buy_price);
-
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
+  for (let i = peak_start; i < 14; i++) {
+    if (!generate_individual_random_price(
+            given_prices, predicted_prices, i, 1, min_randoms[i - peak_start],
+            max_randoms[i - peak_start])) {
+      return;
     }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
   }
   yield {
     pattern_description: "Large spike",
@@ -345,9 +413,8 @@ function* generate_pattern_2(given_prices) {
       break;
   */
 
-
-  buy_price = given_prices[0];
-  var predicted_prices = [
+  const buy_price = given_prices[0];
+  const predicted_prices = [
     {
       min: buy_price,
       max: buy_price,
@@ -358,32 +425,11 @@ function* generate_pattern_2(given_prices) {
     },
   ];
 
-  var min_rate = 8500;
-  var max_rate = 9000;
-  for (var i = 2; i < 14; i++) {
-    min_pred = Math.floor(min_rate * buy_price / 10000);
-    max_pred = Math.ceil(max_rate * buy_price / 10000);
-
-
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-      min_rate = minimum_rate_from_given_and_base(given_prices[i], buy_price);
-      max_rate = maximum_rate_from_given_and_base(given_prices[i], buy_price);
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
-
-    min_rate -= 500;
-    max_rate -= 300;
+  if (!generate_decreasing_random_price(
+          given_prices, predicted_prices, 2, 14 - 2, 0.85, 0.9, 0.03, 0.05)) {
+    return;
   }
+
   yield {
     pattern_description: "Decreasing",
     pattern_number: 2,
@@ -423,8 +469,8 @@ function* generate_pattern_3_with_peak(given_prices, peak_start) {
     }
   */
 
-  buy_price = given_prices[0];
-  var predicted_prices = [
+  const buy_price = given_prices[0];
+  const predicted_prices = [
     {
       min: buy_price,
       max: buy_price,
@@ -434,130 +480,30 @@ function* generate_pattern_3_with_peak(given_prices, peak_start) {
       max: buy_price,
     },
   ];
+  let probability = 1;
 
-  var min_rate = 4000;
-  var max_rate = 9000;
-
-  for (var i = 2; i < peak_start; i++) {
-    min_pred = Math.floor(min_rate * buy_price / 10000);
-    max_pred = Math.ceil(max_rate * buy_price / 10000);
-
-
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-      min_rate = minimum_rate_from_given_and_base(given_prices[i], buy_price);
-      max_rate = maximum_rate_from_given_and_base(given_prices[i], buy_price);
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
-
-    min_rate -= 500;
-    max_rate -= 300;
+  if (!generate_decreasing_random_price(
+          given_prices, predicted_prices, 2, peak_start - 2, 0.4, 0.9, 0.03,
+          0.05)) {
+    return;
   }
 
   // The peak
-
-  for (var i = peak_start; i < peak_start + 2; i++) {
-    min_pred = Math.floor(0.9 * buy_price);
-    max_pred = Math.ceil(1.4 * buy_price);
-    if (!isNaN(given_prices[i])) {
-      if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-        // Given price is out of predicted range, so this is the wrong pattern
-        return;
-      }
-      min_pred = given_prices[i];
-      max_pred = given_prices[i];
-    }
-
-    predicted_prices.push({
-      min: min_pred,
-      max: max_pred,
-    });
+  if (!generate_individual_random_price(
+          given_prices, predicted_prices, peak_start, 2, 0.9, 1.4)) {
+    return;
   }
 
-  // Main spike 1
-  min_pred = Math.floor(1.4 * buy_price) - 1;
-  max_pred = Math.ceil(2.0 * buy_price) - 1;
-  if (!isNaN(given_prices[peak_start + 2])) {
-    if (given_prices[peak_start + 2] < min_pred || given_prices[peak_start + 2] > max_pred) {
-      // Given price is out of predicted range, so this is the wrong pattern
-      return;
-    }
-    min_pred = given_prices[peak_start + 2];
-    max_pred = given_prices[peak_start + 2];
+  if (!generate_peak_price(
+          given_prices, predicted_prices, peak_start + 2, 1.4, 2.0)) {
+    return;
   }
-  predicted_prices.push({
-    min: min_pred,
-    max: max_pred,
-  });
-
-  // Main spike 2
-  min_pred = predicted_prices[peak_start + 2].min;
-  max_pred = Math.ceil(2.0 * buy_price);
-  if (!isNaN(given_prices[peak_start + 3])) {
-    if (given_prices[peak_start + 3] < min_pred || given_prices[peak_start + 3] > max_pred) {
-      // Given price is out of predicted range, so this is the wrong pattern
-      return;
-    }
-    min_pred = given_prices[peak_start + 3];
-    max_pred = given_prices[peak_start + 3];
-  }
-  predicted_prices.push({
-    min: min_pred,
-    max: max_pred,
-  });
-
-  // Main spike 3
-  min_pred = Math.floor(1.4 * buy_price) - 1;
-  max_pred = predicted_prices[peak_start + 3].max - 1;
-  if (!isNaN(given_prices[peak_start + 4])) {
-    if (given_prices[peak_start + 4] < min_pred || given_prices[peak_start + 4] > max_pred) {
-      // Given price is out of predicted range, so this is the wrong pattern
-      return;
-    }
-    min_pred = given_prices[peak_start + 4];
-    max_pred = given_prices[peak_start + 4];
-  }
-  predicted_prices.push({
-    min: min_pred,
-    max: max_pred,
-  });
 
   if (peak_start + 5 < 14) {
-    var min_rate = 4000;
-    var max_rate = 9000;
-
-    for (var i = peak_start + 5; i < 14; i++) {
-      min_pred = Math.floor(min_rate * buy_price / 10000);
-      max_pred = Math.ceil(max_rate * buy_price / 10000);
-
-
-      if (!isNaN(given_prices[i])) {
-        if (given_prices[i] < min_pred || given_prices[i] > max_pred) {
-          // Given price is out of predicted range, so this is the wrong pattern
-          return;
-        }
-        min_pred = given_prices[i];
-        max_pred = given_prices[i];
-        min_rate = minimum_rate_from_given_and_base(given_prices[i], buy_price);
-        max_rate = maximum_rate_from_given_and_base(given_prices[i], buy_price);
-      }
-
-      predicted_prices.push({
-        min: min_pred,
-        max: max_pred,
-      });
-
-      min_rate -= 500;
-      max_rate -= 300;
+    if (!generate_decreasing_random_price(
+            given_prices, predicted_prices, peak_start + 5,
+            14 - (peak_start + 5), 0.4, 0.9, 0.03, 0.05)) {
+      return;
     }
   }
 
@@ -620,6 +566,27 @@ function analyze_possibilities(sell_prices, first_buy, previous_pattern) {
   generated_possibilities = Array.from(generate_possibilities(sell_prices, first_buy));
   generated_possibilities = get_probabilities(generated_possibilities, previous_pattern);
 
+  for (let poss of generated_possibilities) {
+    var weekMins = [];
+    var weekMaxes = [];
+    for (let day of poss.prices.slice(2)) {
+      weekMins.push(day.min);
+      weekMaxes.push(day.max);
+    }
+    poss.weekGuaranteedMinimum = Math.max(...weekMins);
+    poss.weekMax = Math.max(...weekMaxes);
+  }
+
+  generated_possibilities.sort((a, b) => {
+    if (a.weekMax < b.weekMax) {
+      return 1;
+    } else if (a.weekMax > b.weekMax) {
+      return -1;
+    } else {
+      return 0;
+    }
+  });
+
   global_min_max = [];
   for (var day = 0; day < 14; day++) {
     prices = {
@@ -637,31 +604,12 @@ function analyze_possibilities(sell_prices, first_buy, previous_pattern) {
     global_min_max.push(prices);
   }
 
-  generated_possibilities.push({
+  generated_possibilities.unshift({
     pattern_description: "All patterns",
     pattern_number: 4,
     prices: global_min_max,
-  });
-
-  for (let poss of generated_possibilities) {
-    var weekMins = [];
-    var weekMaxes = [];
-    for (let day of poss.prices.slice(2)) {
-      weekMins.push(day.min);
-      weekMaxes.push(day.max);
-    }
-    poss.weekGuaranteedMinimum = Math.max(...weekMins);
-    poss.weekMax = Math.max(...weekMaxes);
-  }
-
-  generated_possibilities.sort((a, b) => {
-    if (a.weekMax < b.weekMax) {
-      return 1;
-    } else if (a.weekMax > b.weekMax) {
-      return -1;
-    } else {
-      return 0;
-    }
+    weekGuaranteedMinimum: Math.min(...generated_possibilities.map(poss => poss.weekGuaranteedMinimum)),
+    weekMax: Math.max(...generated_possibilities.map(poss => poss.weekMax)),
   });
 
   return generated_possibilities;
diff --git a/js/scripts.js b/js/scripts.js
index 24f1376..65cf904 100644
--- a/js/scripts.js
+++ b/js/scripts.js
@@ -65,9 +65,10 @@ const fillFields = function (prices, first_buy, previous_pattern) {
 
 const initialize = function () {
   try {
-    const prices = getPrices()
-    const first_buy = getFirstBuyState();
-    const previous_pattern = getPreviousPatternState();
+    const previous = getPrevious();
+    const first_buy = previous[0];
+    const previous_pattern = previous[1];
+    const prices = previous[2];
     if (prices === null) {
       fillFields([], first_buy, previous_pattern)
     } else {
@@ -101,14 +102,65 @@ const isEmpty = function (arr) {
   return filtered.length == 0
 }
 
-const getFirstBuyState = function () {
+const getFirstBuyStateFromQuery = function (param) {
+  try {
+    const params = new URLSearchParams(window.location.search.substr(1));
+    const firstbuy_str = params.get(param);
+
+    if (firstbuy_str == null) {
+      return null;
+    }
+
+    firstbuy = null;
+    if (firstbuy_str == "1" || firstbuy_str == "yes" || firstbuy_str == "true") {
+      firstbuy = true;
+    } else if (firstbuy_str == "0" || firstbuy_str == "no" || firstbuy_str == "false") {
+      firstbuy = false;
+    }
+
+    return firstbuy;
+
+  } catch (e) {
+    return null;
+  }
+}
+
+const getFirstBuyStateFromLocalstorage = function () {
   return JSON.parse(localStorage.getItem('first_buy'))
 }
 
-const getPreviousPatternState = function () {
+const getPreviousPatternStateFromLocalstorage = function () {
   return JSON.parse(localStorage.getItem('previous_pattern'))
 }
 
+const getPreviousPatternStateFromQuery = function (param) {
+  try {
+    const params = new URLSearchParams(window.location.search.substr(1));
+    const pattern_str = params.get(param);
+
+    if (pattern_str == null) {
+      return null;
+    }
+
+    if (pattern_str == "0" || pattern_str == "fluctuating") {
+      pattern = 0;
+    } else if (pattern_str == "1" || pattern_str == "large-spike") {
+      pattern = 1;
+    } else if (pattern_str == "2" || pattern_str == "decreasing") {
+      pattern = 2;
+    } else if (pattern_str == "3" || pattern_str == "small-spike") {
+      pattern = 3;
+    } else {
+      pattern = -1;
+    }
+
+    return pattern;
+
+  } catch (e) {
+    return null;
+  }
+}
+
 const getPricesFromLocalstorage = function () {
   try {
     const sell_prices = JSON.parse(localStorage.getItem("sell_prices"));
@@ -123,10 +175,10 @@ const getPricesFromLocalstorage = function () {
   }
 };
 
-const getPricesFromQuery = function () {
+const getPricesFromQuery = function (param) {
   try {
     const params = new URLSearchParams(window.location.search.substr(1));
-    const sell_prices = params.get("prices").split(".").map((x) => parseInt(x, 10));
+    const sell_prices = params.get(param).split(".").map((x) => parseInt(x, 10));
 
     if (!Array.isArray(sell_prices)) {
       return null;
@@ -141,15 +193,45 @@ const getPricesFromQuery = function () {
       sell_prices.push(0);
     }
 
-    window.price_from_query = true;
     return sell_prices;
   } catch (e) {
     return null;
   }
 };
 
-const getPrices = function () {
-  return getPricesFromQuery() || getPricesFromLocalstorage();
+const getPreviousFromQuery = function () {
+
+  /* Check if valid prices are entered. Exit immediately if not. */
+  prices = getPricesFromQuery("prices");
+  if (prices == null) {
+    return null;
+  }
+
+  console.log("Using data from query.");
+  window.populated_from_query = true;
+  return [
+    getFirstBuyStateFromQuery("first"),
+    getPreviousPatternStateFromQuery("pattern"),
+    prices
+  ];
+};
+
+const getPreviousFromLocalstorage = function () {
+  return [
+    getFirstBuyStateFromLocalstorage(),
+    getPreviousPatternStateFromLocalstorage(),
+    getPricesFromLocalstorage()
+  ];
+};
+
+
+/**
+ * Gets previous values. First tries to parse parameters,
+ * if none of them match then it looks in local storage.
+ * @return {[first time, previous pattern, prices]}
+ */
+const getPrevious = function () {
+  return getPreviousFromQuery() || getPreviousFromLocalstorage();
 };
 
 const getSellPrices = function () {
@@ -165,7 +247,8 @@ const calculateOutput = function (data, first_buy, previous_pattern) {
     return;
   }
   let output_possibilities = "";
-  for (let poss of analyze_possibilities(data, first_buy, previous_pattern)) {
+  let analyzed_possibilities = analyze_possibilities(data, first_buy, previous_pattern);
+  for (let poss of analyzed_possibilities) {
     var out_line = "<tr><td class='table-pattern'>" + poss.pattern_description + "</td>"
     out_line += `<td>${Number.isFinite(poss.probability) ? ((poss.probability * 100).toPrecision(3) + '%') : '—'}</td>`;
     for (let day of poss.prices.slice(1)) {
@@ -180,6 +263,8 @@ const calculateOutput = function (data, first_buy, previous_pattern) {
   }
 
   $("#output").html(output_possibilities)
+
+  update_chart(data, analyzed_possibilities);
 }
 
 const update = function () {
@@ -193,7 +278,7 @@ const update = function () {
 
   const prices = [buy_price, buy_price, ...sell_prices];
 
-  if (!window.price_from_query) {
+  if (!window.populated_from_query) {
     updateLocalStorage(prices, first_buy, previous_pattern);
   }
 
diff --git a/manifest.json b/manifest.json
new file mode 100644
index 0000000..94f06a7
--- /dev/null
+++ b/manifest.json
@@ -0,0 +1,19 @@
+{
+	"name": "Turnip Prophet - ACNH Turnip Tracker",
+	"short_name": "Turnip Prophet",
+	"description": "An app to track your Animal Crossing: New Horizons turnip prices daily!",
+	"start_url": "index.html",
+	"display": "standalone",
+	"background_color": "#def2d9",
+	"theme_color": "#def2d9",
+	"icons": [
+		{
+			"src": "/img/192.png",
+			"sizes": "192x192"
+		},
+		{
+			"src": "/img/512.png",
+			"sizes": "512x512"
+		}
+	]
+}
diff --git a/service-worker.js b/service-worker.js
new file mode 100644
index 0000000..e68b22d
--- /dev/null
+++ b/service-worker.js
@@ -0,0 +1,90 @@
+// PWA Code adapted from https://github.com/pwa-builder/PWABuilder
+const CACHE = "pwa-precache";
+const precacheFiles = [
+	"/index.html",
+	"/js/predictions.js",
+	"/js/scripts.js",
+	"/css/styles.css",
+	"https://code.jquery.com/jquery-3.4.1.min.js",
+];
+
+self.addEventListener("install", function (event) {
+	console.log("[PWA] Install Event processing");
+
+	console.log("[PWA] Skip waiting on install");
+	self.skipWaiting();
+
+	event.waitUntil(
+		caches.open(CACHE).then(function (cache) {
+			console.log("[PWA] Caching pages during install");
+			return cache.addAll(precacheFiles);
+		})
+	);
+});
+
+// Allow sw to control of current page
+self.addEventListener("activate", function (event) {
+	console.log("[PWA] Claiming clients for current page");
+	event.waitUntil(self.clients.claim());
+});
+
+// If any fetch fails, it will look for the request in the cache and serve it from there first
+self.addEventListener("fetch", function (event) {
+	if (event.request.method !== "GET") return;
+
+	event.respondWith(
+		fromCache(event.request).then(
+			(response) => {
+				// The response was found in the cache so we responde with it and update the entry
+
+				// This is where we call the server to get the newest version of the
+				// file to use the next time we show view
+				event.waitUntil(
+					fetch(event.request).then(function (response) {
+						return updateCache(event.request, response);
+					})
+				);
+
+				return response;
+			},
+			() => {
+				// The response was not found in the cache so we look for it on the server
+				return fetch(event.request)
+					.then(function (response) {
+						// If request was success, add or update it in the cache
+						event.waitUntil(
+							updateCache(event.request, response.clone())
+						);
+
+						return response;
+					})
+					.catch(function (error) {
+						console.log(
+							"[PWA] Network request failed and no cache." + error
+						);
+					});
+			}
+		)
+	);
+});
+
+function fromCache(request) {
+	// Check to see if you have it in the cache
+	// Return response
+	// If not in the cache, then return
+	return caches.open(CACHE).then(function (cache) {
+		return cache.match(request).then(function (matching) {
+			if (!matching || matching.status === 404) {
+				return Promise.reject("no-match");
+			}
+
+			return matching;
+		});
+	});
+}
+
+function updateCache(request, response) {
+	return caches.open(CACHE).then(function (cache) {
+		return cache.put(request, response);
+	});
+}