What is the Learn German A1-A2-B1-B2 Free application, how does it work?

According to the introduction of MobCrab, Learn German A1-A2-B1-B2 Free is a Education app on the Android platform. There is currently a 7.5 version released on Feb 26, 2020, you can see the details below.

Attention! You have found the best of the best learn German application. What makes this app stand out from others?
- It’s 100% free
- Lots of great exercises in A1, A2, B1 and B2 level. Practicing this app is a great preparation for your exam
- You can use it online and offline
- Great app to improve your vocabulary, grammar
- Free correction

Let’s try this app and you will love it for sure!

What's new in version 7.5 - Additional more exercises
- Optimize the application