[jcynix]

You aren't the only one. Those "fancy" apps are too complex IMO to be trustworthy. Neither are other people's computers (aka clouds).

My secrets are stored in plain text files which are encrypted with GnuPG. Emacs (and vi too) can handle encrypted files easily, even on an Android device using the Termux (i.e. Debian) app. Syncing with rsync (even version control software is an option) works and with a bit discipline is not a major problem.

[signal11]

This is literally what pass(1) does. Although it's rather fun to write a bunch of shell scripts that provide equivalent functionality.