When it comes to the note taking apps, I'm afraid that I've tried them all. Really. All of them. So I know everything when it comes to note-taking apps, lol. In my case, I preferred the app called "Notes Plus". It was a wonderful app during version 2.X of it - but it has been updated to version 3.0 as of a week or two back.
app has EVERYTHING you'll ever need. Trust me! Making shapes (lines, circles, triangles etc) is a breeze since it automatically figures out that you want to make a line, or circle - and transforms your "so-so" painted line or circle into a proper good looking computer-made form instead. It's simply much easier especially during math courses, since you'll end up with perfect diagrams and figures every single time!
So, I suggest you guys go and check it out! It's dirt cheap on the App Store! And oh, did I forget to mention the fact that you can purchase an add-on within the app to get access to "handwritten to computerwritten text" aswell?