The best way to learn new words and phrases is to use them actively. The next-best way to learn new words is to be exposed to them as much as possible. And since the wallpaper that adorns my graphical desktop environment is what I stare at most of my waking hours, I thought that it'd only make sense to add words and phrases I want to memorize there.
Half an hour after the eureka moment, I had a working hack consisting of a plain text file with words and phrases along with their translations, a wallpaper template PNG file, and a simple Bash shell script. The latter pulls a random line from the text file, and uses the template to generate a new wallpaper with the picked line. Below are all the gory details worth knowing if you want to roll out something similar.
Hald CLUT files offer a quick and easy way to apply effects to photos, and there are plenty of desktop applications that can handle the task. But if you want to use your favorite Hald CLUT files on an Android device, you'll quickly discover that there are not that many apps (if any at all) that allow you to do that. No problem: instead of relying on a third-party proprietary app, you can roll out your own solution using Termux.
I use my Android device for a lot of things: from booking train tickets and checking weather forecasts, to... Well, pretty much everything else. But for some reason, I've never seriously considered it to be useful as a camera tool. While I was tinkering with Termux, it occurred to me that it can transform an Android device into a camera companion that can perform both photo backup and processing duties.