I had a bike accident which prevented me from typing with my left hand for a couple weeks (dislocated shoulder, broken finger). I wish this were around at the time! I had looked into physical half-qwerty keyboards, but I couldn't afford one.

I ended up hobbling together a simple app that switched two full system key layouts while holding the spacebar, more or less mimicking the half-qwerty behavior. It was my first Mac app, and it was pretty crashy, but it kept me working for those couple weeks.

I wanted to open source it, but ceased work when I was able to type with both hands again, because I knew half-qwerty was patented and didn't want to take that risk.

Really glad there's an easier solution now!