Since iOS 7 was released on Sept. 18, more than two-thirds of iOS users have upgraded to Apple's new mobile operating system, which introduced a new interface and a slew of new features. And while most users seem happy with the update, there have been a few persistent problems.Among the issues most widely reported is a Lockscreen security flaw identified by Germany's Chaos Computer Club. Apple fixed that problem within days, but there have also been complaints that iOS 7 drains battery life, the keyboard lags and there's an issue with iMessage.These glitches don't undermine the fact that the iOS 7 launch has
