Works Perfectly! I lost Night Mode on my Nexus 5X because once the preview build was updated to final Android 7.0 I factory reset the phone. This app made it show right back up for me. I was even able to uninstall this app after hitting enable. I decided to donate a dollar to the developer because this was a life saver for me. The night mode was the best new feature in the preview  and I really started to rely on it.
August 31 2016