I think this is a good idea because it is both simple and useful. There are lots of possibilities and I like that you already have the option for private or public flashcards.
Here's the thing: you HAVE to update the design. This is very 1990s geocities and honestly plain white space with black text would be better. The logo truly hurts my eyes. And the text that randomly shakes... just no, please. Sorry if I sound harsh but I'm dead serious - I could not in good conscious send people there even if that's what they needed (at least without a disclaimer, or not even then)
Here's the thing: you HAVE to update the design. This is very 1990s geocities and honestly plain white space with black text would be better. The logo truly hurts my eyes. And the text that randomly shakes... just no, please. Sorry if I sound harsh but I'm dead serious - I could not in good conscious send people there even if that's what they needed (at least without a disclaimer, or not even then)