Apple has included functionality in iOS 7 that allows for the physical mute switch on iPhone to be used for controlling portrait orientation lock. As a result, the orientation lock toggle in Control Center is replaced with a mute button. However, the feature is disabled by default.
As discovered by iFans forum member tw23, the feature can be re-enabled through some simple plist editing. Those interested need to first plug in their iPhone and backup using iTunes. While this initial step plays a role in enabling this modification, it also serves as a precautionary measure in case anything goes wrong.
Next, you’ll want to download iBackupBot for OS X or Windows. This program should automatically detect the backup you created using iTunes. Navigate to /HomeDomain/Library/Preferences under System Files, and open com.apple.springboard.plist.
Add the following strings under <dict>:
You’ll then want to press the save button, or the red power button if it isn’t working, from the top toolbar. Now, go back to iTunes and press the “Restore Backup…” button. iTunes will then backup the modified version of iOS 7 you just created, which usually takes 30 seconds or less.
This entire process can be done without a jailbroken device, and shouldn’t erase any data or settings from your iPhone. Having said that, this is a simple hack that does have the potential to mess up your device. Apple would also consider your warranty void for making these modifications, so this should be done at your own risk.
It is unknown if Apple had originally planned to include this orientation lock functionality on iPhone, or if these strings were included solely for iPad. Apple is still making minor tweaks and bug fixes to its iOS 7 beta software ahead of the public release next fall, so there remains room for change.