When I first started learning Japanese, I started on another app (not sure if I can say the name here). It was enough to make me believe it was possible, but seemed slow and limited.
Then I discovered anki cards. It was OK for vocabulary and kanji learning, but seemed a bit vague.
Finally I found Renshuu, and I use it since then. It's a very complete "app". There's lessons, games, statistics, quizzes. Above all of that, there is a community of people, willing to help each other.
I don't really have a "good reason" to learn Japanese. I don't have plans to live in Japan and zero conditions to visit it (お金がはい). But it like the Japanese culture, I feel good being part of Renshuu community, and occupying my mind with learning helps me dealing with my anxiety problems.
So, you all help me with my mental health and entertainment too.