Your Flowing Data Uploader was a free iOS app that functioned as a simple front-end for Your Flowing Data, a very cool self-surveillance application by Nathan Yau. His application allowed users to log data points about themselves by sending a DM to the @yfd account on Twitter, which was at the time new and cool.
The YFD Uploader app stored users' commonly used shortcuts and allowed them to customize them. The app then used the Twitter API to send this information directly to Your Flowing Data, where folks could visualize it using Nathan’s very cool data visualizations.
The iPhone SDK debuted with iPhone OS 2.0 (now iOS) in March of 2008. Your Flowing Data Uploader was launched in the summer of 2009, and received regular updates to support new iOS features like Core Data in iOS 3.0, and Fast App Switching and the Retina Display in iOS 4.0. It also received regular updates to support Twitter API changes as they came down the pike.
Your Flowing Data Uploader ended its run in the App Store in 2012.