Android phones and tablets. "In addition, the Android smartphone operating system (from version 4.0 onwards and possibly earlier; we don't know for sure when t

Android phones and tablets. "In addition, the Android smartphone operating system (from version 4.0 onwards and possibly earlier; we don't know for sure when the change happened) uses GPSD to monitor the phone's on-board GPS, so every location-aware Android app is indirectly a GPSD client."