Link goes to 3 min. YouTube video of me playing Scarlatti (K159) on the gadgetina, a homebrew MIDI keyboard. The gadgetina is actually an old project, but the video is new. [more inside]
I made a custom keyboard for iOS called Translit Keyboard that lets you transliterate English into Russain, Ukranian, Armenian, Belarusian, Georgian, Greek, and Macedonian in real time. (Transliteration is phonetic: you type "raz, dva, tri, chetyre" and get "раз, два, три, четыре".) The keyboard is based on a simplified reproduction of the iOS system keyboard built in Swift, called Tasty Imitation Keyboard, that I have open-sourced. It could be used to build custom keyboards similar to Translit Keyboard fairly easily.
To quote myself from the page: "Most MIDI keyboards look like cheap toy spaceships from 1982. But music production is now a home activity. Here’s a keyboard you'd be proud to have around."