Apple has just pushed out yet another incremental update to iOS 7, but there's no need to brace yourself, as this is a minor bug fix patch.
The update is called iOS 7.0.4, but it's also identified as "build 11B554a". According to the official release notes from Apple, the update features "bug fixes and improvements, including a fix for an issue that causes FaceTime calls to fail for some users".
The update is available for iPhone 4, iPhone 4S, iPhone 5, iPhone 5C, and iPhone 5S. It's also for the iPad 2, iPad 3, iPad 4, iPad Air, iPad mini, and iPad mini with Retina display. Apple further released iOS 6.1.5 for the fourth-generation iPod touch - which cannot run iOS 7 - to fix the same FaceTime issue.
You can get the updates now by powering on your device, going to the native Settings app, then the Software Update section, and tap download and install.
Apple has released iOS 7.0.4 just three weeks after iOS 7.0.3. That big update notably added support for iCloud Keychain and fixed accelerometer issues.