I'll second the biggest drawback of Yousician, Id say to anyone whos reading this and its an absolute beginner first time picking up an instrument... do not buy this.. you will spend some time, maybe months learning to play alongside tabs in front of you and thats it, you will not remember any songs and it will actually be harder when you transition away from Yousician to learn full songs. Train your brain in a more traditional way and once you are in the process of surpassing the beginner stage you can safely start using apps ;) my 2 cents.
I'm using Guitar Learning Game app on my iPhone, and it's alright. Looks similar to yousician guitar with the sliding fretboard, but has a lot of extra fun features.
