I like using syncthing. It syncs all my apps that are backed up with neobackup, my pictures, files etc. to my NAS. Then my NAS runs borg on that directory as well as all the other important NAS directories to make the legit backups.

I have termux installed but I honestly rarely use it. Hate typing on the phone in the terminal… if I need to do it then I’ll just adb connect from my computer and do it from there on a real keyboard.