[Android][App] Obtainium. Get Android App Updates Directly From the Source.
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.
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.