Here is an interesting project which illustrates how to use the 1Shield with Arduino and your Smartphone. This example is a knock-code lock for the door. Using a smartphone to transmit a knock-code is definitely not the optimum solution, but its just a demo (as Ashraf Nabil himself explains) and you can use it to interface your own 1Shield.
I happen to forget my phone more often than i forget my keys, and since i forget my keys more often than i forget numbers, i made a Touchpad KeyCode Lock for my door.