The new version of the ru15k deck has just been released. This post contains instructions for existing users of the original ru15k who wants to update to the new version. If you are a new user, or only studied a small number of cards from the original ru15k, you can also simply delete the original deck and start using this deck directly, which would not require any manual intervention.
Here is a compiled list of primarily immersion based learning resources for Russian, some of which I have used myself.
The information is not guaranteed to be correct. If you would like to correct anything, please join our Matrix chatroom and give your suggestions. (link on the sidebar)