Gospel Library problem

I am stuck in general conference mode. How do I get back to the main menu?

By "general conference mode," do you mean you're stuck in the list of talks, in a general conference talk, watching a general conference video, or something else? Normally, in Gospel Library for Android, there should be a back button at the top left of the screen. You can also tap the titlebar at the top of the screen to see a navigation menu, and from there jump to the main library or anywhere in between the library and where you are in the app.