Well, Apple has a bit of egg on its face right now. Seems as if an update to the Find My iPhone app has been pushed out to some devices before it was ready for consumers. The update brings that pretty new matte icon that is part of the iOS 7 make over, but it also brings with it the inability to log in to the service without a developer account. That's right, this update was meant only for devs, but it's being pushed out to at least some members of the public. When users go to try and log in an error message pops up informing them that "you must be a registered iOS developer and have iCloud configured on iOS 7.0 Beta to use this version of Find My iPhone." We've reached out to Apple from comment, we're expecting something along the lines of "oops...
Update: Apple hasn't issued a formal statement, but we've been told the issue has been fixed. Best of all, there's no update required -- users who have updated should just be able to log in now.

http://www.engadget.com/2013/08/22/f...breaks-log-in/