The idea behind OpenAPK - https://www.openapk.net is to follow the app developer releases directly by serving unmodified official binary downloads! All updates are available right on the after the release (no need to wait for F-Droid build). By installing official binary downloads signed with the developer signature you avoid signature mismatch issues caused by F-Droid builds for example.
For most app there is an Obtainium download badge of you want to follow the updates automatically.
For most app there is an Obtainium download badge of you want to follow the updates automatically.