After having purchased all the tracks (for about $20 Canadian) in the past, the game would occasionally crash. It was manageable at that time. However, this morning after having not used the app in a while, the tracks would not even so much as load. No attempt at fixing it would work. I have since deleted the app. Save yourself the hassle and the money of this app.
(Jaydge) about Zumba Dance, v1.52