Here's a list of recommended apps! They are extremely helpful :)
If you have any other recommendations, feel free to write it in the comments!
I have read mixed reviews about duolingo, but I personally love it. It keeps me active with the language even it is 5 min a day (specially for the busy days). The stories make it the best, as I'm able to practice reading, vocabulary, and speaking. Best of all is Free!
NHK News is one of the best apps out there to practice reading and hence vocabulary. The most helpful part to me is the fact that each story is linked to the JLPT levels, so you can always read something that will fit your Japanese level. It also has translations to the news, so in case you get lost, you can verify your understanding! Pretty neat!
Weblio is one of my favorites. What makes it so good? Well, very simple. It is a Japanese - Japanese dictionary. For advanced learners trying to learn new vocabulary and its usage, weblio will offer that. You just type in your words and it will give you very straightforward sentences that match your word.
Although, I don't use it that often, it is a very promising app. You can play Japanese music videos which the Japanese lyrics and follow along. It also has translations and furigana, so you don't lost. If music is your thing and your preferred method to learn, this is the perfect app for you.