Swag Sensor is the best way to trick your friends into thinking your iPhone can check yo swag! Simply choose one of the three sensors, point the device at someone, and let the Swag Sensor do the rest.
Of coarse, the iPhone cannot actually measure swag, so here is how it works. When a sensor is chosen, Swag Sensor will initialize the direction of maximum swag towards you (the user of the device). This way, if you turn and point the device at yourself, it will read "maximum swag". However, if the device is pointed directly away from you (presumably your friend), it will read "no swag". All this is made possible with the iPhones internal magnetometer.
Go and download Swag Sensor to check you swag!