Magellan Corporation was the inventor of portable GPS devices. Their first such device, the Magellan NAV 1000, was introduced in 1989. The satellite navigation system that powered Magellan's system was completed in 1995.
In 1999, the Benefon Esc! from Benefon became the first cellular phone to include a portable GPS. In-car navigation systems from Garmin and Tom Tom followed two years later; both companies introduced competing vehicle GPS units in 2001.
The Department of Defense intentionally lowered the accuracy of GPS signals from 1990 until 2000. Once this program ended, GPS became more accurate and was widely adopted in consumer products and industry.