Could be a very good app
This app could be an excellent tool to support your study of a language. The app has quirks like using a word that has two meanings and then later when asked for its definition the word isnt given in context so you have no way of knowing which definition the app wants.
More troubling is the fact that not all of the functions in the app work. I have the premium edition. This coupled with poor customer support (I wrote to them about this problem and didnt receive a response), results in a mediocre rating from me.
Boccherini about
Learn Spanish with Busuu, v3.4.1