Formscanner is a free, open-source software for scanning and grading user-filled, multiple choice forms. Formscanner is easy to use, effective, and completely free of cost and advertisements. Users scan the forms and, in just a couple of steps, they have a spreadsheet with students' scores, answers to individual questions, and detailed analysis of the class' perfomance.
This site contains links to the Formscanner & other requisite software, a quickstart guide, forms & form templates, and video tutorials on how to scan your own forms.
Check out our poster from the 2015 Winter meeting of the American Association of Physics Teachers.