Appear offline allows you to set your status to show you as “offline” to your gamer friends while remaining connected to the internet. This means you can launch the app and game away without distraction.

Appearing offline will show you as offline to everyone on your gaming friends list. Once you have joined a game, the experience of appearing offline might be slightly different depending on which game you are playing. In the case I played The World of Warcraft, your guildmates will not see your character come when not online and when you enter WoW’s in-game offline, anyone who has you as a character-level friend will never see you're online friends' list. Everyone outside of the same game as you will not see you when you're not online or playing any games.