deepceleron is 100% right. The heavy lifting is done by Bitcoincharts.com, as I clearly stated in the app's description on Google Play :


I just pull the image with your favorite settings from this website and display it into a widget.
You would have the same result opening your browser using a bookmark.

The added benefit of the widget is in fact to be able to flip through a few timeframes (5 days, 10 days, 3 months, etc) in a few clicks on the widget.
Also, it's always on your homescreen and can be resized to your taste. You can even set it on your lock-screen.

I'm not trying the reinvent the wheel as Bitcoincharts.com does a fantastic job generating the charts. I give them 200% credit and full respect for this !