How people are using the crazy-popular app that just passed Snapchat to reach the top of the App Store

MiiTomo, Nintendo's first smartphone game, has become an overnight hit.

The app has generated over 3 million downloads worldwide, and it's already unseated Snapchat as the top free app in Apple's App Store.

Part game, part social-media platform, MiiTomo's hook revolves around creating a "Mii" avatar using your smartphone's front-facing camera, and then answering questions that can be seen and favorited by your friends.

But the game's breakout feature seems to be its photo mode, called "MiiFoto," which lets players customize the position and expression of their Mii avatar and place them on top of any background. 

This also includes any image from your camera roll, leading to real-life-meets-video-game mashups. Here are some examples of how people are using MiiTomo creatively.