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.
It can replace fdroid with caveats. Direct download from gitlab/hub/codeberg/fdroid official with searching. Other git/fdroid repos with manual web addy entry. Good for stuff both on and off fdroid.