Sololearn is one of the best application for learning any programming language. It basically requires a facebook account to connect or mobile number to register. This app basically clears all the doubts with regular test and quizzes. Anyone can compete with any other guy on this site.
I have been using this app for a long time and learning languages, it help Me a lot in learning languages. With this app I have learned basics of Java, c, c+ , html and currently I am learning python from this app. The best feature according to me in this app is that it gives certificate when we pass in all the quizzes and if we use this app daily we will get xp everyday.
According to me this is one of the best app to learn new programming language with all the basics. ????