Computer games giant Nintendo has launched its first smartphone app in Japan, a mobile-only game and social tool that centres around the Mii user avatars created on its popular Wii and WiiU gaming consoles.

Miitomo is a free app that enables users to import their existing Mii or create a new one, customising them with different hair styles, outfits and more, some of which cost real money. Users can post comments and photos, heart each others posts and make use of a number of other social network-style functions.

“We believe we created a number of elements that are very sticky for the consumer,” said Reggie Fils-Aimé, president of Nintendos US division. “If we are successful in creating something sticky and shareable, we believe it will break through.”

Nintendo has conspicuously avoided publishing any games on mobile so far, despite its huge fanbase. Despite some critical support, the WiiU has failed to compete in the console market against Sonys PlayStation 4 and Microsofts Xbox One, and mobile may serve as a way for the firm to shore up its finances while it works on a next-generation console, currently code-named NX.

The company has plans to expand Miitomo to other markets including Europe and the US, but hasnt announced any schedule for the rollout. Mobile game revenues are expected to grow 37 per cent over the next four years, reaching $48bn (£33bn) in annual revenues by 2020. Despite this, when the game was first announced, Nintendos shares dropped nine per cent.