App for takling notes in ppt?

Im a student and a couple of times I've seen another student taking notes within the power point presentation om her iPad. She writes with a pen, draws and uses the keyboard to take notes. I would like to have the same opportunity, it seems like a god way to note, instead of the pen-and-paper-way.

I haven't seen her in a while, so can't ask her ... Help!

Any suggestions?

Thank you!