This app has been super helpful in my Spanish learning. Really easy to use and the lessons are just repetitive enough to increase language mastery, in my opinion. I'm currently on my 16-day streak and going strong!
I adore Duolingo! I even feel as an ambassador because some of my friends also join studying after me.
What I like the most is that Duolingo constantly evolving their mechanics. So you won't be bored.
I'm with Duolingo since 2016, finished Italian course twice! And now I'm also have more that half of a thousand streak.
Duolingo helps me to be multilingual
Decent as a crutch for learning languages, although you should also practice the languages outside of it. It can be unstable at times, although that seems to be improving in recent versions.