How to Enable "Unknown Sources" on Your Nexus 7 for Access to Awesome 3rd-Party Apps
Google's Play Store is packed with some great apps, but since we're the rebellious types looking to fully utilize the capabilities of our Nexus 7s, we're going to need some 3rd-party apps—apps that can't be found in the Play Store. Don't worry, it's not some sketchy way to acquire black-market apps. This function serves conventional purposes, like getting the exclusive Nexus 5 Google Launcher on your Nexus 7. By enabling Unknown sources, we can acquire device-specific apps with ease.
Go into Settings -> Security > then check Unknown Sources. Feeling liberated yet?
Now we're ready to install third-party apps—checkout some of the mods that rely on Unknown sources