I've been working on an android version of an existing iOS app that we worked on at The App Business a couple of years ago. I've also been working on a new like feature where users can like photos within the app.
The idea behind the animation is for the heart icon to fade into view and catch the users attention once they've stopped on a photo they could potentially like. Once the heart has been pressed it will fill with the flavor colour that the photo was tagged with.
I've also been visually updating the iOS version to feel at home with iOS 7, which I can share in the next few weeks.