Images filed alongside the patents suggest development of the app is well underway and suggest it may be aimed at children.
The patents, which cover technicalities of the app such as the way it allows users to select colours for their avatar, have prompted speculation that Apple could be working on its own video gaming service, or that it could be part of a forthcoming Apple TV upgrade.
The images in the patent filings show the avatar app running on an iPad.
"The three-dimensional models can be constructed from the combination of several assets such as a body, a head, eyes, ears, nose, hair, glasses, a hat, or other accessories," say Apple's filings.
"To enhance the user's experience, the user can personalize a displayed model by selecting and moving specific assets."
The avatars on Nintendo's Wii are known as Miis and are used to identify the player's account at home and online. Some titles such as the Wii Sports series allow users to play as their digital likeness.
