There is a thread elsewhere that posed some interesting questions. I wanted to comment without worrying about not being able to quote my own post, so I'm commenting here. I'm also interested in kikenyoy's opinion, since he is a skilled Thai learner, and Cainntear's opinion, since he is also developing something (top secret?). If you get a chance, please read the old thread. Here is the recent question: This sounds similar to a mouse-over dictionary that uses statistics. LingQ does something similar, and I find it extremely useful. Something LingQ does that yours doesn't (I think) is color code (by shading) unknown and previously looked-up words. LingQ does some other things too, but that's the only useful thing they have that you don't, imo. The thing that your tool has that LingQ doesn't is the connection to an SRS, rather than just a bare-bones statistic program. This will appeal to lots of people. Your flashcards will be SRS, whereas LingQ flashcards are very basic. But I have to admit, there are things about an SRS based learning program that don't appeal to me. It's some sort of bias that I have against doing to many flashcards. I normally advise people not to let flashcards get to be over 25% of their total study time. But if the whole program is in an SRS - yikes! And part of this bias comes from years of dealing with Supermemo and Anki. SRS's are so unforgiving. Have a couple bad sessions, and the whole collection could spin out of control, and the user could be facing a nightmarish quantity of repetitions. So have you thought of this? Are you going to give the user a way out? If he's sick, can he skip a day without increasing his workload? I had several arguments with Damien (Anki creator) about this. He refused to allow Anki to do a time shift; said the user should make up the repetitions. This isn't realistic, imo. Anyway, he ended up adding the ability to put an upper limit on reps per day for a given deck. At first, I refused to use that, because it obviously violates the analog when you hit the limit. But since it was the only solution I had, I finally gave in and started using it. It seems to work pretty well.