[aagat]

I have been using pass[https://www.passwordstore.org/] for two years now and it works reasonably well.

Desktop "GUI": rofi-pass[https://github.com/carnager/rofi-pass]

Android Client: https://f-droid.org/packages/com.zeapo.pwdstore/

Sync: Git+Manual download

All components are open source and actively maintained.