As part of the Android Operative system, there is a restriction that blocks installing applications outside the Google Play Store.
If it's your first time installing an App not from the Google Play Store, you're greeted with, "Install blocked. For security, your phone is set to block installation of applications not obtained from Play Store" message as you try to install. But how do we get there?
To allow app installs, follow these steps:
That's all, now you can try again to install the Application.