How to continue learning Japanese
After completing the Japanese course, how can you continue learning it?
Genki is all you need, pretty much the best books out there
You can try watching movies (don't worry if you don't understand them, you are unconsciously getting information, you can also try listening to music.
For listening practice i highly recommend this:
You can continue learning it in a number of ways. There are a ton of online free resources, my personal favorites being the courses at Memrise and TanoshiiJapanese. Speaky and Hellotalk are all great exchange apps and websites, and there are many free dictionaries including my favorite and probably the most effective, Jisho. If you want some iOS apps, Kanji Teacher is a great way to learn kanji, and the best dictionary out there is probably Imiwa? (Yes, the question marker is included). There are many more apps and websites to list and use, but those are some of the most effective ones that I have found over the past few years.
There are probably some good Japanese resources on here: https://www.reddit.com/r/languagelearning/wiki/index