this was the first thing I noticed as well. I think the extra space required for words is worth the lack of confusion.

Agreed. If space is really an issue at least use "T" and "H".

Thanks for the feedback. And yes it's one of those things that might or might not work out.

I figured since the app is so simple and there is practically no features I could get a way with the user figuring out how to use it.

If it gives problems I will change it. But so far those who have tried pretty quickly found out.