Anyone ever play "Dope Hunter"? Actually I forgot what it was called exactly, but it was like a Legend of the Red Dragon type game, except you were a drug dealer, and it worked on TI-81s.
I agree with the OP that iPads currently restrict most users to being consumers, rather than programmers...but I'll admit, I didn't know many people who finagled around with creating or modifying TI programs...we mostly just distributed programs, downloaded from the Internet (or BBSes) among ourselves. However, the interface of a calculator was (understandably) pretty painful, so I think some of the more industrious of us did hack our own routines for common calculations. Even that kind of rudimentary programming/problem-solving isn't possible from the iPad or its more popular educational apps.