Awesome app. It is somehow not listed on android-foss list so maybe someone didn’t know about it.
Obtainium allows you to install and update Open-Source Apps directly from their releases pages, and receive notifications when new releases are made available.
GitHub page: Link.
Only reason I installed it is for it’s ability to use GitHub releases as a source and notify me if there are updates. As far as I’m aware you have to use f-droid repositories with f-droid – but it’s been a long time since I had f-droid installed.