Fixed in iOS 7.1 beta
Previously, text drawn with CTFrameDraw did not correctly place lines to account for the paragraphSpacing attribute of NSParagraphStyle. This has been addressed in iOS 7.1 beta.
Crash Logs
Known Issue
Crash logs will not appear in Diagnostics & Usage Data in Settings. The logs will still be available when synced off the device.
GLKit
Fixed in iOS 7.1 beta
If loaded with GLKTextureLoader, pngcrush images that have alpha were not unpremultiplied.
High Precision Timers
Fixed in iOS 7.1 beta
When sleeping or waiting for extremely precise time intervals, timers were delayed by up to 1 millisecond.
iTunes