Miitomo

Miitomo was a social networking mobile application developed by Nintendo for Android and iOS and released worldwide in March 2016. The app allowed users to communicate with friends by answering questions and sharing images. The game also featured a "Miitomo Drop" minigame, in which players could "drop" Miis for a chance to win in-game clothing items or candy. Several promotional items based on were made available through official promotions while the Fancy Party vs. Costume Party Splatfest was held in May 2016 to promote Miitomo.

Miitomo was discontinued on 2018-05-09.

Splatoon and Miitomo
On 2016-04-20, Nintendo started a Splatoon retweet event. Several Tweets across Nintendo's Twitter accounts were made announcing that if they were retweeted 10,000 times, Miitomo players would receive an in-game Inkling boy wig. If 20,000 retweets were made, players would also receive an Inkling girl wig.

From 27 April to 2016-05-29, two Splatoon-themed Miitomo Drop stages are available, allowing users to obtain Splatoon-themed clothing items. Also during this time period, players could redeem Miitomo coins for squid pin accessories, or redeem My Nintendo Platinum Points for ink tanks. Both were available in various colors.

On 2016-07-05, the original Splatoon content was made available again (until 2016-07-14 for the Miitomo Drop stages and 2016-07-15 for all other content) and new shirts based on the Callie and Marie Splatfest clothing were added to the Miitomo shop.

S+ Fashion! Splatoon Theme [A]

 * Tentatek Trainers
 * Squid Tee
 * Inkling Girl Shorts
 * The shorts of an Inkling girl. Comes in orange, blue, lime green, purple, turquoise, and pink.
 * Inkling Girl Wig
 * The hair of an Inkling girl. Comes in orange, blue, lime green, purple, turquoise, and pink.
 * Inkling Girl Shorts
 * The shorts of an Inkling girl. Comes in orange, blue, lime green, purple, turquoise, and pink.
 * Inkling Girl Wig
 * The hair of an Inkling girl. Comes in orange, blue, lime green, purple, turquoise, and pink.
 * The hair of an Inkling girl. Comes in orange, blue, lime green, purple, turquoise, and pink.

S+ Fashion! Splatoon Theme [B]

 * Inkling Boy Wig
 * The hair of an Inkling boy. Comes in blue, orange, lime green, purple, turquoise, and pink.
 * Zink Layered LS
 * Inkling Boy Shorts
 * The shorts of an Inkling Boy. Comes in blue, orange, lime green, purple, turquoise, and pink.
 * Hi-Horses
 * Hi-Horses

Trading Miitomo coins

 * Orange ink tank
 * Blue ink tank
 * Lime green ink tank
 * Purple ink tank
 * Turquoise ink tank
 * Pink ink tank

Shop accessories

 * Squid Badge. Comes in lime green, turquoise, orange, purple, blue, and pink.
 * Splatfest Tee (Callie)
 * Splatfest Tee (Marie)