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.
Are you aware of the izzyondroid repo? That contains loads of github releases which for one reason or another haven’t made their way to fdroid yet. So far, I haven’t had to manually download any apks from github because everything has been available there.
I use it, but I have some games that are not there and only at github/gitlab.
Lots. But definetly not all releases. Very convenient app!