I've just spent the last hour struggling to work out how to use BoxCryptor Classic on my new Android phone. As a last resort, I checked this forum and realised that 5 months ago I posted the same problem I'm having now! Seriously, what's the point of having a forum if no-one bothers responding?!
If anyone is able to help me, I'd greatly appreciate it.
By the way, I would highly recommend that you include a help option in the Android BoxCryptor Classic app, so that questions like this are unnecessary. Users should not have to rely on guesswork alone to work out what "an upwards arrow with a line under it" means or how to use it.