Dumb Ways to Die is a great example of how to market iPhone applications. They have taken the core game concept and characters and turned it into a catchy video. As a result, it’s very shareable and sparks your interested about the game. At over 63,000,000 views and nearly 70,000 ratings I think it’s working.
Link to the iPhone game – https://itunes.apple.com/app/dumb-ways-to-die/id639930688