In addition, I’d like the possibility to have multiple answers to one question and the need to know all of them / keyboard type them correctly.
Let me give you an example: I am currently learning Hungarian, and often the accusative form of nouns is irregular. So, when I create an entry for a noun, I have to enter both options. Eg: "fal (falat)"
Now, the problem is that Memrise does not ask me to keyboard enter both. It treats such things as a sentence, and the learning is much more passive (just recognizing amidst other options) than with single words.
A related improvement (already suggested elsewhere on the forum) is to have entries force you into giving all different options. Example: in Hungarian there are 3 ways to say “sorry”: “bocsánat / elnézést / bocs”. My request would be that Memrise forces me to give all three answers as translation for sorry.
Finally, I would appreciate it if the app became much more sociable, like suggested above. I like the competition element in Duolingo or Mondly for example. Connect with all others who are learning the same language at roughly the same level, through leadership boards, discussion forums, chats.
Finally, if I may, a bold suggestion: could Memrise try to acquire Lang-8 and add it to her services? I love this website, it is very sociable and helps you to improve writing skills in a foreign language. As for usability though, Lang-8 could improve greatly by becoming part of the Memrise team.