Here are some resources that may help.
Elizabethtown College – Top 10 Best Apps for Instructors and Staff
Consumer Reports – 19 Top Free Apps for College Students
PC Magazine – The 100 Best iPad Apps for 2014
TeachThought Editor’s Choice: The Best Educational Apps for iPad in 2014
Here are some apps that we like:
Kahoot.it (free) – Turns mobile devices into a clever student response system for the classroom.
Noteability ($2.99) – A note taking app that allows you to annotate PDF documents and will also record audio.
Explain Everything ($2.99) – A powerful interactive whiteboard app that can annotate documents from Word, Excel, PowerPoint and PDF. You can also put together screencasts (a recording of what you are doing on the screen along with the audio) which makes this app perfect for quick instructional videos.