A free app for Android, by Ecco24.
This application is intended to be used as a learning aid and for practicing your speech. It contains a lot of information about verbs and their conjugation. In the first part of the application, you will find definitions and examples of verbs. The verb will be presented in a text and you will have to guess the verb. If you get the correct answer, you will be rewarded with points. You can use the points to get a better understanding of the concept.
In the next part, you can choose between a dialogue and a text mode. In the dialogue mode, the app will read the sentence that you have just typed. In the text mode, you can type a sentence by yourself.
The app can be used in offline mode and contains a built-in trainer.