I use my foldable bluetooth keyboard. Using iAWriter and termux, I can write posts for my PHP and ruby based blogs, run my static site generator and publish via git. Termux lets you make a shortcut that runs commands.
I tried to make gtk3 GUI apps with ruby on termux, apparently termux now supports this new mode that works in the browser, but some libs seem to be missing! I think that would be a cool platform.