I sent it out to parents of violinists in an email as a suggestion of a way to help their children practice some more. I didn't expect a flood of emails saying how amazing it was or how much it helped, but I did get an email this afternoon from a parent who said it was a great way for her daughter to study in the long car ride to the ski resort! They pulled it up on their iPad as they drove to Western Maryland and she study the 8 simple flashcards for 10 minutes and took the quiz feature on my set of cards. Her daughter, Lizi, said it helped a little bit and could already notice improvement.
I had also not tried the quiz feature on the site, but it pulls up one side of the card and gives a 4 multiple choice options as to the definition. If they click on a wrong answer, it turns red, and gives them another chance. At the top the site keeps a score of how well they did getting some pretty quick feedback.