Cool site!
I think you should have a more efficient UI for either skipping a word or showing the hint. For apps where the user is expected to interact intensively with the system, it pays off to have special ways to save even a few seconds of time per interaction. For example if I were going to use the system for five hours, I would guess that I would waste 10-20 minutes in aggregate time moving my hand to the mouse to click on the "show hint" button.
Hitting the 'escape' key is the same as clicking on 'Show Hint'. It isn't explained very well on the site; I will do better.
I agree very much with your sentiment. Once you start practicing, your hands should not leave the keyboard.
I've been wanting to learn Mandarin Chinese for years now and just recently I wrote a small website to help me practise.1 All of the exercises are gap sentences that require you to type the correct answer before you can move on. I chose this kind of exercise because of the convincing evidence for the spacing effect and the testing effect.
Knocking through a bunch of exercises every day feels efficient but it's not exactly fun and I put in less time than I should. I've found two things that help with this: setting small and achievable goals, and reading short stories once I'm proficient with the vocabulary. And if there are two ways to make practicing more fun, there gotta be a lot more that I haven't thought about. So, how do I make myself work harder? Are there are any of the so called Dark Arts that are more than hearsay and could work in my favor? How do you people out there learn foreign languages and how do you keep yourself from giving up or slowing down? Do you use the pomodoro technique?
Cheers, David.
[1]: https://talentsrs.com
Edit: more on -> move on.