Language Learning apps are not bad, but wasting your time there is easy. Why? This is primarily because of the gamification of learning. Duolingo offers a good base for starting to learn a language. It’s motivation to learn every day to keep your strike, and the longer you are online, the more you want to keep this strike. There are also leagues where you get promoted to a higher level. This easily leads to an addiction in the form of scoring as many points as possible and less meaningful learning of words and phrases. Repeating a wrong written word directly after a minute helps you get a perfect lesson in Duolingo, but it’s not helpful in making progress in your learning process.
My personal advice: Think about why you’re using Duolingo. Is it a game for you, or do you want to learn? If you’re going to learn, forget about remaining in the highest league or even achieve a podium finish. Keep your learning strike, which means you’re learning at least once a day for a minimum of time.