Vortprovizo is Esperanto for vocabulary. And we have given this application this name because it is hoped that it will help you build your vocabulary.
Vortprovizo uses pictures to do this. It shows you a word or short phrase, and if possible, plays audio of it's pronounciation. There are also a series of photos shown. You then need to choose the correct photo. That is the hard part. Most people don't like to be wrong, but being wrong can be a very good tool for learning.