Personally I found the tests repetitive and very quickly got bored with it. It feels like a research project and not like a game where you would get a reward or having much fun really.

This app is hard to use as a stand alone resource, I needed to use the British Sign language resources as the videos move too fast. I also found you can't read the subtitles and see signs at the same time, and many didn't gave subtitles when they should have. Some auditory feedback would help for none visual-kenesthetic learners. Everyone learns differently so these subtle changes would help.

I use this on my tablet and phone and it's great!