Busuu is one of the most versatile language learning applications in comparison and also describes itself as a "social network for languages". Here, classic learning games and short lessons meet strong community integration with several million active users. You can therefore always choose to practice reading or listening comprehension during the lessons, practice vocabulary with Busuu's vocabulary trainer or practice speaking and writing with tandem partners in the community. Busuu's presentation is very professional and is geared towards the CEFR levels A1-B2 - but is sometimes a bit dry. This is especially true for the grammar exercises, which Busuu has a lot of. All in all, however, Busuu offers a very successful concept, which is even available free of charge in a lighter basic version. However, as it lacks not only comfort features such as the offline mode or the vocabulary trainer, but also essential parts of the lessons, you should at least consider a premium account. In the most expensive "Premium Plus" subscription you also have the option of purchasing a language certificate from McGraw-Hill.