However, the few times I've really wanted to delve into math and really understand the concepts underpinning that formula I'm using, I need a machine to iterate on. My computer isn't ideal because the software that's available is too expensive for 'hobby' use; there's no library that lets me use code in a language I know to manipulate symbols and equations. The TI series of calculators are not ideal because A) they're intentionally crippled (to prevent student cheating) and B) they have a bit of learning curve to them when you don't use them regularly.
Can I get a touch-device app for mathematical symbol/equation manipulation? That'd be ideal.