How to enable "Unknown sources" on your Android
In order to install SMS Tracker from our website, you will need to enable "Unknown sources" in the settings on your phone. Depending on the version of Android you have, this could be in one of several places.
Android 4.x
Settings > Security > "Unknown sources"
Android 2.x
Settings > Applications > "Unknown sources"
Simply click on the checkbox for "Unknown sournces" in order to enable it.