Coruscation checks all installed Sparkle-enabled apps for updates. It's released under a BSD license.
It uses private Launch Services API to list all apps, checks each found app's bundle info dictionary for SUFeedURL, then instantiates a SUUpdater to do the check. It uses a customized Sparkle FW (forked at GitHub — use the included get_sparkle.sh shell script to clone it next to Coruscation) to suppress some error alerts (among other things; see Read Me.txt in the project for details).
