Miitomo now has more than 1 million users, earned in just three days after its initial launch on March 17 in Japan.

Miitomo is Nintendo's first mobile app initiative and seemed to have surpassed the success of the company's hub type messaging platform known as Line. Moreover, it is one of the most popular apps in the iOS charts after reaching the top spot in app ranking.

"Miitomo is a uniquely entertaining mobile experience that only Nintendo can deliver," says Scott Moffitt, the Executive VP of Sales and Marketing of Nintendo America. "Featuring Mii characters, users will be able to interact with their friends in an entirely new way that transforms communication into a form of play."

The Miitomo app features the Mii characters that Nintendo fans met through the company's Wii system. Users can choose from a huge selection of facial features to create a Mii character that will resemble their own physical attributes. Another way of creating one is through the use of a mobile device camera.

Other things that users can do with their newly created Mii character include giving it a nickname; customizing how the Mii character speaks, behaves and moves; and creating new looks from the Miitomo shop's huge collection of costumes and formal fashion wear.

"Mix and match clothing items to create looks that your Mii will wear when visiting friends, hanging out in your room, and appearing in Miifotos," states the app's description in iTunes.

Users can share their Miifoto creations on popular social network sites that include Facebook, Twitter and Instagram.

Nintendo is also launching its new My Nintendo rewards program, which should allow account holders to connect with the app. The new service will be accessible in 16 countries and is set to come in two unique tiers.

The first tier will be known as Gold Points, which users can get from purchasing Nintendo games, digital content and consoles. The second tier will be Platinum Points, which can be earned every time the user logs into his My Nintendo account, plays a game on his device and does any other non-transaction activities.

The app is initially available on Apple devices such as the iPhone, iPad and iPod touch. Users are required to have iOS 7.0 or higher in order to start using Miitomo. An Android launch of the app is said to occur real soon.