How to install unknown source APK apps on Android
By default, your Android device won’t allow you to run apps from an unknown source, but this isn’t a difficult issue to fix – it should only take a minute. Being able to run APK apps from third-party sources means you’re not restricted to just Google Play Store as the source for all of your apps and games, so here’s how to do it.
First off, go to the “Settings” page and select “Additional Settings”. After that, go to «Privacy», then click on «Special app access», this is regarded as a “Security” issue on the grounds that Google can’t verify the apps and games from third-party sources, but in reality our apps are perfectly safe.
Click on “Install unknown apps” and this should open up a new menu, where you’ll see “Brower” (or the browser you use to download the APK file) as one of the choices. Simply click on “Allow from this source” to enable your Android device to install third-party APK apps.
Once you’ve done this, then you should be free to install and operate apps and games from all sources, not just Google Play Store, which is what owning an Android is all about – total freedom.