Epic For Educators - Epic Win!
There is a HUGE range of books available from first readers to non-fiction to enjoy. The app also provides incentives through badges and achievements given when children reach a certain goal.
Probably the best thing about Epic is that for teachers it is completely FREE!
All you have to do is visit the website and create an account and then download the app! Log in once the app is downloaded and you have access to a wealth of online books!
Here is the link to create an account - Epic Website
Here is a link to the iOS app - Epic for iPad