Many of these apps are excellent in their own right. They do exactly what the developers say they will. They are note taking apps, but, one or two do a little more. The Soundnote app I have blogged about before and is an interesting take on multimedia notetaking. It is something that I have used to keep digital voice recordings as minutes to meetings.
Another that I think offers more than expected is iStudious. It's a complete note taking app designed for students and performs in a similar way to other apps. You can create notebooks for each class and organize the notebook by lectures etc. iStudious is, however more than just another note taking app. After you have spent the time organising your notes you can then turn them automatically into flashcards that help you study the information you have just recorded.
It is great to see app developers continually improving their product and looking for ways to improve the educational outcomes of the students who use their apps. iStudious is well worth a look