If you like to mod your Nexus devices but you're also a fan of tight security, you probably already know BootUnlocker. It's a simple app that allows rooted devices to lock and unlock the bootloader without wiping user data. The developer, segv11, is back with v1.5.1 of this handy little utility. The latest update adds support for the WiFi (flo) and LTE (deb) variants of the 2013 Nexus 7 and the ability to set the tamper flag on the Nexus 4 (mako) and Nexus 5 (hammerhead).
Prior to this update, BootUnlocker supported every Nexus device since the Galaxy Nexus with the notable exception of both generations of the Nexus 7. It is known that the original Tegra-based version from 2012 will probably never be directly supported due to technical limitations, it's great to see the Qualcomm-based 2013 Nexus 7 variants joining the list.
A new feature to BootUnlocker is the ability to toggle the tamper flag. In a recent OTA, the Nexus 4 and Nexus 5 began setting this flag if the bootloader were unlocked and "tampered with." Just like locking and unlocking the bootloader, this is achieved by modifying a byte of data stored in the param or misc partition. While it's unlikely that Google or LG are denying warranty claims on these devices, it doesn't hurt to play it safe in the event you have to return a device for a physical defect.
BootLocker is freely available from the Play Store, just hit the widget below. You can also pick up the source code from Google Code if you're interested in seeing how it works. Happy flashing!