where to buy cheap good cellphone gps?

Rencently i bought a cellphone online, and i want to install a gps tracking system on it. It is said that cell phone manufacturers installed GPS receivers into their cell phones and now there is a feature called enhanced 911 that enables emergency opperators to instantly see the location of the caller even if they call in on their cell phone.
And i was heard about one cellphone gps tracker called: "Find My iPhone" is an application that can be used on either the iPhone, iPad, or even the iPod Touch to locate them in the event that they're lost are stolen. It's sounds really nice,but now i need a gps tracker compatible with a wide variety of phones. So i was wonder if anyone can recommend a good site for me, and do you think stores online with Wholesale China Electronics are saling good quality china products? I saw many of electronics store like - ecargoonline.com are sale many kinds of gps trackers with cheap price, but i still want to compare the price and the quality.