It's not clear if the developers are simply trying to build a free alternative to Duolingo, but I'm not a fan of that approach anyway.
I tried Duolingo, but it was really just a flashy form of rote memorization. I had much greater success using Language Transfer, which is also free but is a series of MP3s.
Maybe this could be used in conjunction with LT, the former for vocabulary and the latter building up grammar and processing skills.