Android camera app for papers.
All the math for the app is explained in my book called Geometry for Programmers.
Schedules, announcements, notes, book covers etc. Just use menu button to take a picture, and your touchscreen to mark a frame. Pictures will be stored in Docam folder.
Also, there is a more advanced desktop app that can even unbend book pages: https://github.com/akalenuk/unpager