Nintendo announced earlier this year that they are partnering up with Japanese company DeNA to release five mobile games by March 2017, and the first game was set to launch sometime this year. During Nintendo's second quarter investor briefing (ongoing as this is being written), President Tatsumi Kimishima announced that this release date has been pushed back to March 2016.
Afterward, he announced that this first mobile game is called "Miitomo." It's a free-to-play game with in-app purchases that stars Nintendo's Mii characters. Players will design Mii characters, and the Mii characters will then communicate with each other and share information without your knowledge, which Kimishima and Nintendo executive Shinya Takahashi say will help people who are hesitant to talk about themselves to communicate with others and will reveal a side of your friends you never knew. Nintendo also confirmed that some of their mobile games will have a pay-to-download price model.
Source: The Wall Street Journal