App vs Web
It seems that the App does increase the percentage of how fluent you are. Now that I use the web it goes up, Secondly it seems that the Web questions are more difficult, i.e. You have to write entire sentences in the foreign language whereas the App gibes more simple multiple choice questions. If that was fixed, I would be happy, as the app is much better to use.
Web and app version work indeed differently, so what would you exactly like to have fixed? The web version is better in my opinion: You learn more and better because of its higher degree of difficulty.
Alex, the app is more convenient to use on a mobile device (this is where I use Duolingo). However, functionality seems to work only on the Website. This is what I was trying to say.