English study app

I am studying English with a smartphone application on my commuting time.
The name of the app is “duolingo”.

It heard that it is a very popular app, so I installed it on my phone.
When I actually did it, I can study it easily, so it’s very good.

However, it is necessary to have more time to know either it really improves English skill or not.

NIFS Web-master (English Beginner)