Calculus teacher Brighid Boyle recently asked me if there was a way to superimpose graph paper over an image on an iPad so students could measure objects that they captured with the camera. After some research I came up with a solution thanks to this blogpost by Mr. Reisler. He suggests using the superimpose app ($0.99) to take an image and overlay transparent graph paper. After testing this workflow, I discovered that it was fairly easy to complete this task. I then added Skitch to the equation so that students could annotate and measure the objects directly on the iPad. Plus, all the sketch ups in Skitch automatically sync to Evernote.
Below is a video I put together outlining the aforementioned operations. If you have any questions, please post in the comments.