The Find My iPhone app caused problems earlier today due to its recent update. A possible glitch made login impossible for non-developers. The requirement was hosting iOS 7 Beta on your device which many people are lacking right now.
Fortunately, Apple fixed the error but some are still complaining about the access. This may just be a minor flaw on Apple's usually flawless record but could raise concerns about the latest version of its OS. The more unusual/interesting part is that this one of the first major redesigns we've seen for the new system. It's puzzling though why Apple would choose to apply this to an app first instead of something more integral to their product line. The firm may have pushed out a developer-centric program too early.
Apple's website shows that they have fixed every issue but could still be updating as we speak.
The final iOS 7 Beta is expected to be released with two new iPhones on September 10.