Update README.md

README.md

@@ -10,7 +10,9 @@ Forked and refactored from [HTTP Switchboard](https://github.com/gorhill/httpswi
 
 Install [manually](https://github.com/gorhill/uMatrix/blob/master/doc/README.md) the [latest release](https://github.com/gorhill/uMatrix/releases), or install from:
 - [Firefox AMO](https://addons.mozilla.org/firefox/addon/umatrix/)
+    - To help find issues with ongoing development: [uMatrix dev build on AMO](https://addons.mozilla.org/en-US/firefox/addon/umatrix/versions/beta)
 - [Chrome store](https://chrome.google.com/webstore/detail/µmatrix/ogfcmafjalglgifnmanfmnieipoejdcf)
+    - To help find issues with ongoing development: [uMatrix dev build in Chrome store](https://chrome.google.com/webstore/detail/umatrix-dev-build/eckgcipdkhcfghnmincccnhpdmnbefki)
 - [Opera store](https://addons.opera.com/en-gb/extensions/details/umatrix/)
 
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