Just as an update, Unlimited is fully working on my laptop with Chrome, and on my Android phone. The voice recognition is far better on the phone, so I think I'll be doing my challenges on there.
I love Lingvist and have progressed enormously since using the app. I think it is by far the best learning tool I have used.
I know you have enough to do at the moment, but as a possible suggestion for the future, is it possible to have an archive section in the challenges so you can re-do challenges more than once.... or am I just sad wanting to do this!!
Keep up the good work.