I'd heard great things about this app from friends, I went to the site, made my cards to study for my state licensing exams, and downloaded the app. I was eager to try it, and bummed when the app crashed. I emailed support, which responded within a day. Together we troubleshooted to try and get it working, and they had me send in the crash report. The guy from support was great, he emailed me daily for a week to give me updates, and then let me know when they fixed the issue. I downloaded it, bought my unlimited flips, and love the app.
You can mark them as right, wrong, or flag them. It's a clean, easy app to use, and pretty inexpensive. You get 100 flips for free, you can buy 500 flips for $2.99, or do the unlimited for $5.99. If you're studying for anything major or still in school, it's a really useful app. I'll recommending it to my friends who are also studying.