Post-it Plus is a free iPad app that I demonstrated for someone at the ISLMA conference yesterday. It's a great iPad app (you have to have iOS 8) that you can use to turn your physical sticky notes into digital sticky notes. With this free app installed on your iPad you can snap a picture of a collection of physical sticky notes and have them quickly digitized. Once your notes are digitized you can re-arrange them, share them with collaborators, or send them to another application like Dropbox. If you have multiple sets of notes you can combine the best notes into one board on the Post-it Plus iPad app.
Applications for Education
Post-it Plus could be a good app for digitizing the output of a brainstorming session that started with physical notes. In a classroom in which only the teacher has an iPad or there are only a few iPads you could have students carry-out brainstorming sessions with physical notes then go around the room with one iPad to create a digital record of those notes. Then project the app through an LCD projector or interactive whiteboard to show students all of the notes and talk about which notes should be sorted into various categorized boards in the app.