OOcharts is the Simple API for Google Analytics. It is an awesome little project that makes it easy to embed and share Google Analytics data through charts. API Keys are created to give access to certain Google Analytics profiles. For every request to OOcharts, you will need a valid API Key.
They queue your requests that would normally exceed the Google Analytics™ API limits to ensure you get your data fast and reliably. They also cache requests so you don’t have to waste time waiting for the same report you asked for a couple seconds ago. As soon as you connect your Google™ profile and make an API Key for your site, you can start getting data. You can fork OOcharts on Github too.