StreetPass

Streetpass is a built-in feature in the Nintendo 3DS. When the user puts their 3DS into sleep mode (closing it while it's still powered on (does not work in DS Mode)), and passes another 3DS in sleep mode, the two systems will transmit a small amount of game data that the user has selected to send. This data could be Travelers from Tomodachi Life, Ghost Data from Mario Kart 7, and much more. The main use of StreetPass was in the built-in application called StreetPass Mii Plaza, where players could send short greetings, their recently played games, their Mii, and data from it's DLC games.