Join Date:Joined: Jul 2013
You didn't tell us why you can't install the app through the Google play store. If your Play store app is broken, you should remedy that first. If you are trying to install it onto an unsupported device, then you could download the Nexus firmware and extract the app from the firmware archive.
A simple Google search would also find copies, although it's a challenge to discern the integrity of an app from an unknown source.