The Nexus 9 is still a new device, but it's a Nexus, and that means developers are going to tinker with it. In order to flash ROMs and whatnot, you need a custom recovery. Now there is one for this device. An official build of TWRP is live, and it brings some changes that take into account Lollipop's new security measures.

nexus2cee_wm_DSC05626

Here's the changelog for TWRP 2.8.2.0.

  • Pull in all changes from Android 5.0 lollipop into TWRP
  • Add decrypt support for Android 5.0 lollipop encrypted partitions including automatic decrypt when the default_password is in use
  • Revert some changes to exFAT that were breaking exFAT support on some devices
  • Other minor fixes and updates

Installing TWRP on a Nexus device is pretty easy. All you need is ADB/fastboot on your computer and an unlocked bootloader. The image files are available on the TWRP site, but make sure you grab the newest one. Good luck and happy flashing.

[TWRP]