I am not the author.

https://github.com/galdor/github-license-observer

https://addons.mozilla.org/en-GB/android/addon/github-license-observer/

This is a cool little addon to help you tell, at a glance, if the repository you’re browsing on github has an open source license license.

Especially relevant nowadays given the trend to convert previously OS repos to non-OS licenses as a business model (eg Akka or Terraform.)