If for some reason your Android powered smartphone does not perform as good as it used to, or you want to sell it I suggest you to bring it to its original factory state.
Let me show you how to add a Google account to a Samsung Galaxy SIII so you can read you Gmail email, download apps from the Play Store and synchronize you Google Documents.
Airplane mode on a phone is when you disable all the active connections like WiFi, bluetooth and mobile network. Let's see how to enable it so you don't need to turn off your phone on an airplane.