Thank you so much for this. I'm an unabashed linguistic philistine. I see language at best as a useful tool and find no more beauty in it than I do in a hammer. But I'm also a long term expat and I feel kind of rude barging into these countries, taking the jobs and the women and not adapting the culture at all. This is exactly what I need.
Before now I've half-heartedly tried to write a script that would give flash cards based on a combination of word frequency in common texts and the amount of times I've gotten the word correct in the past. It didn't work. I should try your app.