Animal Face Maker does exactly as it sounds -- converting the face of someone in a photograph into that of an animal. It works more or less as advertised, but the interface is fairly rudimentary and the features are limited to the facial edits: It doesn't provide additional tools to customize how your finished photos look before sharing.
When you first open Animal Face Maker you can start crafting faces immediately. Either take a photo or add one from your photo library. You'll need to select or take one with a person looking at the camera to ensure it works properly. After choosing an image, the app will attempt to line up the eyes and mouth of the animal onscreen. You can adjust this, however, making it easier to get it matched up just right. When you're done, it will process your image and the person will have a new, animal face. This process takes almost no time; and while it looks decent, the final images do have the feel of copy and paste. Additionally, the app is lacking some of the editing tools that could allow you to create some truly creative images.
Animal Face Maker delivers on its promise but doesn't do much more, and combined with heavy ad-support in the free app, there are better options on the App Store to choose from.