Charity Miles is an app that I have recently found that is provided both for Android and iPhone. It's an app that donates money to your charity of choice (out of these options) while you run, walk, bike, indoor run, or indoor walk. It's $0.25 for every mile you run and $0.10 for every mile you bike. It was a great motivator for me and I definitely think you should try it out.
What charity would you donate to?