Normally, the top app rankings within the iOS App Store are updated several times every day, but last Friday, Apple froze the rankings for at least eight hours. TechCrunch's Sarah Perez reports, "Though the store has now seen activity resume over the weekend and into Monday, the changes in app rankings now being observed are still unexpected, with historically highly ranked apps dropping 10 spots instead of one, while other previously ranked top 20 apps are unable to achieve ranks higher than 40, in other cases."
The unusual happenings with the rankings could be related to the release of iOS 7, which caused extremely high traffic on Apple's servers. Or Apple could be trying out new ranking algorithms. Because getting into the top ten lists can make or break an app, the mobile development industry is watching the changes to the rankings closely.