Help.

Let us play games together on-demand, games that work immediately.

Link to the tested game or series, with or without screenshot, please.

It works through Galaxy within a game. One person is hosting a game and invite a friend from the Friend`s List.
Another person is accepting the invitation and the game is starting itself (if installed)

I played that way:
Worms W.M.D.
and Metal Slug
Attaching Screenshots with the Invite Option that leads to Screen2.

What are the other games here, with the Immediate Online Multiplayer Invite Button?

Thank you for helping us all to play some multiplayer.