Today Apple released iOS 8.1.3, which brings several stability, performance, and security fixes, including a reduction in the available storage required to install a software update.
You can download the update by visiting Settings > General > Software update from your iOS device.
OS X 10.10.2
Also released today is OS X Yosemite 10.10.2, which brings stability, performance, and security updates, as well as adds iCloud Drive to your Time Machine backup.
To install the OS X Update click the Apple menu, choose App Store, and then switch to the Updates tab.