Stephen Wolfram's recent blog post that presents a visualization of a lot of his life data is opening a lot of eyes. I submitted an app to the original Android Developer Challenge back in 2008 that produced many of the same exact data plots. I called it LifeScope. It contains its own custom graph plotting library and a completely generic data handling backend that you should be able to plug a range of different data sources into.
Stephen Wolfram's blog post has inspired me to clean up my code and get the app out. Please leave a comment if you would find this app useful, and let me know what data sources in your life you would be interested in plotting.