Not enough transcription
Sometimes I go through a whole listen and all I'm doing is translating into English or doing the multiple choice options. I want a way to say "don't give me multiple choice more than twice per lesson, give me more translation INTO the language, give me more listening", it seems to me like your system creates all four types of questions for any given sentence, so it seems like this would be as easy as adding a weight to the random number generator based on user preferences (leave it to me to belittle the job on software engineers. You guys rock!). I feel like this would be an awesome feature, what are the odds we could get something like this in an update?