A few weeks ago, over the Thanksgiving break I made this quick hack to aid with the ergonomics when programming in my iPad (my mobile setup is an iPad pro with Blink Shell and an AMD PC that I mosh into). My default keyboard layout is programmer dvorak with caps lock mapped to ctrl key. I can't get that on the iPad, but I can map the keyboard to Dvorak layout (close enough). However, mapping caps lock to ctrl is really flaky and some times works, some times it doesn't (IIRC Apple broke it a few releases ago). Tired and starting to develop a pain in the wrist, I decided to quickly hack a pedal to type ctrl. I thought it was going to take a lot to get used to it, but I was wrong. It's super intuitive and fun :)
If you want to repro, I uploaded the STL and OBJ to 3D print the base, the firmware and other instructions. Enjoy!