ElegantScience

This is a fantastic chess app - probably the best on the App Store. The biggest problem: I'm just really disappointed that you can play only one game at a time. You should be able to play multiple games you can toggle back and forth between. Right now, it's only one game at a time... Which makes it very slow for playing different positions or openings simultaneously. So that makes it a bit annoying to use as a self-teaching app.