[useruseruser]

Yes, could the OP please elaborate on this? The above mentioned SRS systems are pretty good at what they do and since the learning algorithm really cannot be that sophisticated, I have a hard time seeing how you can improve on them. Also, you don't seem to have native apps. Compare that to, say Anki, which has everything covered from desktop, to web to mobile (although Android only I believe). While yours is a web app, but I don't think it's very nice to use on the desktop (like, cursor is an arrow even on links). It's too mobile oriented, but then you might as well go with a native app.