Let me compare learning English with an app and learning in a class. Both are good ways to practise regularly, and both can be fun. The main difference is the teacher. In a class, a real person corrects your mistakes, whereas an app usually gives you only a score. On the other hand, an app is cheaper, and you can use it anywhere, even on the bus. Personally, I prefer a class, because speaking is easier when someone answers you. That said, I still use an app for ten minutes every morning.