Rated 2 out of 5 stars

Not a fan. In the settings, the option to never hide the alert is greyed out for some reason. If you happen to miss the alert, you're out of luck. Also, the project has been taken off SourceForge for some reason. Not very reliable.

This review is for a previous version of the add-on (3.1.12.1-signed). 

Are you using MacOS?

If so, it was greyed out because the close button didn't work, and I don't have a Mac to test it on. If you'd like to help us to fix this, please raise an issue at https://github.com/sneakypete81/updatescanner/issues