diff --git a/4.1-Extensions.md b/4.1-Extensions.md
index 9c32b97..a3efc30 100644
--- a/4.1-Extensions.md
+++ b/4.1-Extensions.md
@@ -50,6 +50,7 @@ These extensions will not mask or alter any data sent or received, but may be us
    * Why would you want to detect ~~Cloudflare~~ CDNs? Read [this](https://github.com/claustromaniac/detect-cloudflare-PA/blob/master/README.md#motivation).
 * [mozlz4-edit](https://addons.mozilla.org/firefox/addon/mozlz4-edit/) | [Github](https://github.com/serj-kzv/mozlz4-edit)
    * inspect and/or edit `*.lz4`, `*.mozlz4`, `*.jsonlz4`, `*.baklz4` and `*.json` files within FF
+* [CRX Viewer](https://addons.mozilla.org/firefox/addon/crxviewer/) | [GitHUb](https://github.com/Rob--W/crxviewer)
 * [Compare-UserJS](https://github.com/claustromaniac/Compare-UserJS)
    * Not an extension, but an excellent tool to compare user.js files and output the diffs in detailed breakdown - by our very own incomparable [claustromaniac](https://github.com/claustromaniac) :cat2: