Calculator apps are plenty in the App Store but let's face it, most of them don't really stand out.
Xneat's "Solve - Handwriting Scientific Calculator" on the other hand is something of a gem. It's the straightforward calculator we all know with one major difference, it allows you to enter your problem by simply writing it with your fingers.
The numbers and operators are naturally recognized as you're drawing them on your iPhone's screen, and drawing an equal sign will compute the result. Alright, I'm more comfortable with the keypad for now, but the app is pretty impressive.