Books for the ipad

At this point in time I don't have ipads to be used in school, but I have grandkids that love to use mine.  Most of the stories on it are from the app store...until now.  Nook now has a kids' nook app for the ipad.  Now I can get real books-and in color.  There are a few that are 'read to me',  and these I'll get for my preschooler grandson. 

Finally...books I know and can enjoy!