The detectomatic app detects the presence or absence of voltage in 50 or 60 Hz conductors. The app requires the voltomatic sensor, inserted into the iphone audio jack to function. Hold the sensor near the conductor to be tested and the application will flash red in the presence of voltage. The sensor will pick up the presence of voltage without contacting the conductor.
There are settings for the adjustment of the sensitivity of the sensor and the threshold at which the sensor alarms, for use in noisy or heavily shielded environments.