iPhone developer David Muzi has released an update to his Trackr RSS and web reader app, adding support for local file storage and synchronization of stored files to iTunes over USB. The update also now allows files to be previewed directly within the app and adds new social networking services for sharing links to Facebook, Twitter, Instapaper, Read It Later, Google Reader, Delicious and more. Trackr allows users to read RSS feeds and web sites on their iPhone or iPod touch and download any linked files to either the local device storage or upload them to Dropbox directly from within the app. Users of multitasking-capable iOS 4 devices can also continue file transfers in the background and the application also provides iPhone 4 Retina Display optimized graphics and offline RSS viewing capabilities. Trackr requires an iPhone or iPod touch running iOS 4 or later and is available from the App Store for $3.