You must be in android version 4.0 Ice Cream Sandwich or greater, and have an internet connection on your device. Some features are locked. But can be Unlocked watching promotional videos. A must have utility for electrician's, electrical contractors or those looking to pass an electrical certification. Calculations per National Electric Code 2017. Calculations included: Voltage Drop -Circuit’s Conductors voltage drop. -Minimum Conductor Size. Pipe Bend -Offset. -Three bend saddles. -Rolling