Widget Created; Checks If LulzSec Has Leaked Your Email
Yes, there is an app, but it's not a mobile one. Instead, it is a widget, embedded below. All you have to do is enter your email address and it will tell you if your email address exists in any of the information that LulzSec has harvested.
Among the organizations that have been hacked by LulzSec are PBS, Sony, an FBI-affiliated website, the CIA, Bethesda Softworks, Eve Online, Escapist Magazine (gaming) and the list seems to go on and on.
If you're concerned that this in and of itself might be a hack, good for you. That is a valid concern. However, our friends at The Next Web assure us that the developer, who wants to remain anonymous in fear or reprisal from LulzSec, is legitimate and on the up-and-up.
LulzSec seems to respond to Tweets as well; they hacked the CIA after being challenged to do so by a Twitter user.