LONDON (AP) — Smartphones are useful tools for everyday life, but they're privy to nearly everything about you, including all the places you've been — if you let them. When you use a map app to find the new restaurant your friend recommended, or your phone's browser to check the price of something you saw while window shopping, you could be unwittingly allowing your phone to track your location and share that information with others. Phones use various signals to find your location, including cell tower pings, Wi-Fi access points, Bluetooth and GPS.