yes, it still works: i was playing in site, then opened app in mobile, and live game automatically switched to mobile.
switch between mobile app and browser during live game

wish I knew this. did this in tournament game and it resigned when I closed the app
dont close app before opening site, leave app open and then open site, so that app will close automatically

To go from Mobile > online:
you have to:
- go to chess.com
- hover
- Press orange "New game" button, in the top of the container that comes out.
- Done.
Explanation: System will see if it can create a new game for the user that's logged in. Since the same user is currently playing an online game, it won't even show the options for creating a new game, because the same user can't play two online games at the same time, no matter what the platform is, hence, it will continue the game you were playing on your mobile device.
You should be able to. If you are on the app, just bring up the browser and go into Live. It should end the app session and load your game on the web client.
At least, I've seen that work in the past and I assume it still works that way.