Visually, the app is a wholesale ripoff of Face Unlock for Android, although the developer has claimed he built it from scratch. The app works just like Face Unlock for Android, although it is noticeably slower to react when scanning the user's face. And, just like in Android, it will bump you to a pattern unlock if it doesn't recognize your face.
It's a cool proof of concept, but definitely too slow for normal use. Although Face Unlock on Android is pretty gimmicky too, so maybe this app falls in line with what to expect right now. With luck, Apple's solution will be a bit more elegant than this.