I was learning Japanese in Tokyo while also working on a small-business accounting app. Japanese accounting is extremely specific, so even for someone enrolled in classes, there was no way I would be learning all those kanji any time soon. I impressed a Japanese co-worker though, because I quickly learned visually where the buttons I needed to click were so I could copy the app features from iPhone to Android. Turns out you don't have to be able to read almost anything as long as you see something used correctly and can remember button locations visually etc.