Two weeks ago, we got our first look at Miitomo when Nintendo's first smartphone app launched in Japan. Called Miitomo, the app allows users to customize Mii characters like those popularized by Nintendo's Wii Sports. US smartphone owners will have a chance to make their own Miis when the free app hits the App Store and Google Play on March 31st.

As a game, Miitomo is an excuse to collect digital objects — which can be purchased with real currency — and take photos of your Mii. Miitomo asks players questions, and their answers with friends. The Verge's Sam Byford documented his impressions on the game's release in Japan:

What Miitomo does have in abundance is the sleek, appealing quirkiness that Nintendo’s had a knack for ever since titles like Wii Fit and Brain Age. I wouldn’t bet on it becoming the next big thing, but it’s going to be a neat way for Nintendo fans to engage with the company and each other — and it might just be another notable source of revenue, too.

Within days of its release in Japan, Nintendo announced the app had been downloaded a million times. According to Bloomberg, Nintendo's stock leapt 8.2 percent in Japan, its biggest increase in over a month.

Nintendo plans to release four more apps this year, which have been described by the company as more traditional game experiences.