OneDee time clock will be supported by iBeacon, WiFi, GPS, QR code

iBeacon - easy for installation, can verify employee's location in 3 meters
Wi-Fi - use your WiFi for verify employee's location. Depends on the range of your WiFi.
QR code - Print out your company QR code for employee time clock.
GPS - Can be used for outdoor time clock and verify employee's location on the map.

For GPS, the variation of the range about 80-100 meters depends on the GPS signal on mobile phone and can not identify for each level in the building.