Miiverse is a social network that launched with the Wii U platform. A part of the Nintendo Network, it will allow allows for users to connect with friends and with strangers with similar tastes in games. Some games will also contain features that connect the game to Miiverse. One such example scenario is for allowing the display of messages left by others that have died at the same obstacle in the game as the player.
Miiverse will eventually be expanded beyond the Wii U platform, and will allow players to check messages on their Nintendo 3DS, PCs, smartphones and tablets.