Post it notes are a resource that appear in many teachers tool kits, they can be used in so many ways during a lesson, wether as part of a connect activity to see what the students have remembered from a previous or as a exit ticket.
If you use post it notes in class with your students, then this free app will just what your after, the challenge most of us face when using post it notes with our students, is how do we capture the results of the activity with our learners.
With free iPad app you can photograph your display of post it notes , edit them, add extra annotations, add extra post it notes , re-arrange them and then either download them as an image or share them as a PDF. discussions
Here is my video Guide on how to use it.