Music Study Tools!

[Thatfabulousalien]

Two questions in one:

1 Are there any good websites or apps that help you to keep "musically fit" (it's how I'd describe it), like those language learning sites/apps; Where it goes step by step like a course, getting harder and harder? I've already done a lot of theory study, but I want to keep myself 'in the loop' with music education.

2 What are your methods for learning music theory? I'm interested in how you approach it.
I'm personally the kind to study lots of scores and read analysis and 'lecture' books

[ComposerOfAvantGarde]

Answer to question 1: I don't know but it would be cool to find out.

2. I do the same as you. I also like to teach others what I know because then I get to look at other people's ways of thinking in terms of music theory and analysis.

[(poco) Sforzando]

I've been giving this site: https://www.musictheory.net/ a test run, it's interesting but I don't yet know it's depth.
Still not a 'course structured' tool, like I'm looking for though 

The interval training part is pretty good.
https://www.musictheory.net/exercises/ear-interval

Proves to me I still have problems identifying sixths.