A new factory image has been released for the 2013 Nexus 7, which is Android 5.1.1_r6 build LMY48G. This maintenance release likely addresses some issues that users faced with previous builds, though no exact change log is available right now. Currently, this update is only available for the Nexus 7 Wi-Fi model, though we would expect it to become available for other devices in the near future.
In order to get your hands on this new build, you will need to flash the factory image from a computer, as the over-the-air update has yet to begin rolling out. If you are interested in flashing the factory image, but aren't exactly sure of how, be sure to check out our comprehensive guide to walk you through it.