There are a lot of great apps that help me. For absolute beginners, I think Human Japanese is the best, for pronunciation especially. But if you already know the basics, then for learning kanji I'd say apps like Midori or imiwa? are great. c: I wrote a notebook entry about helpful apps, so if you need more go check that out.
There are also a lot of great YouTubers that help with learning Japanese. For grammar and phrases and the likes, Puni Puni Japan is pretty good.
I hope these helped somewhat. ^^