The bread and butter of Zipgrade is camera scanning multiple choice answer sheets. You can download and use their 20, 50, or 100 question “scantrons” (or create your own) and have them instantly graded by the app on your phone.
It does scan rapidly one after the other on the same screen.
The app gives you item analysis for each question. You can grade 100 papers per month for free. Unlimited grading access is only $7 a year.