What are the best apps for teaching and learning?

The following articles and websites list their top choices. When the same app is listed in multiple places, we know we have a winner!!

29 Apps for Teachers: The Educator's Essential iPad Toolkit

Best Apps for Teaching & Learning - 2013 - from the American Association of School Librarians

PC Mag's Top Apps for Teachers

70 Best Apps for Teachers and Students - from Edudemic

35 Favorite Free Apps for Teaching - from Scholastic

50 Fab Apps for Teachers - also from Scholastic, but by subject and not all free!