I got the Nexus Player running PopcornTime and Showbox.

Donwolad the APK's:
HTML Code:
ShowBox: http://www.mediafire.com/download/4wsv5q3t4kanaui/Show_Box_4.04.apk
PopcornTime: http://104.131.187.115/android/0.1.3.1/mobile-armeabi-v7a-release-0.1.3.1.apk
I used adb install /path/to/files to install the applications.

After installed, launch from Chainfires Sideload Launcher

**Note** that if you use PopcornTime you better be behind a VPN. PopcornTime uses P2P torrent technology so that will piss off your ISP and redflag your account.
Showbox is a bit slower but is safer to use without VPN, they are streaming from an actual hosted site.

Happy movie watching,
DFL