I'd also add a couple of other tools:
Pythonista is indispensable for learning/using Python on iOS. 'Python for iOS' is good too-- it isn't as clean as Pythonista, but it does include the python.org language docs with the app. The both utilize python 2.7 and a REPL, but I think there are other versions that use Python 3.
Pythonista and 'Python for iOS' are good apps, with quite different goals than my app. They allow trying and exploring the language and learning to write programs, whereas I aim to teach basic reading skills of programs. Both are important skills.
There nowadays seems to be 'Python x.x for iOS' for almost all recent versions of Python :)
I have pretty small hands/fingers and still end up mis-clicking after periods of use.
Awesome app though, love the skip feature!
In Pythonista and 'Python for iOS' mentioned by ldayley you can execute the code you write. Don't know how they do it, though.
That said, I built the app mostly for fun and learning, so making money -- while a nice bonus -- isn't the main motivator.