F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
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There's one based on Git, but haven't been updated for a while: Git Journal
Using git it's probably the most easy and lightweight method to VC plain text, and you will probably just need to use the git commit command most of the time.
I personally just use a bash script and run it through Tasker and Termux to sync my text notes to GitHub.
Using git it’s probably the most easy and lightweight method to VC plain text ...
Really? I am currently using RCS for my simpler version control needs, and Git for larger and collaborative projects.