Google has released two API for developers to use in third party geolocation apps. You can use the APIs to make your apps location aware, even if the app doesn’t have access to GPS information.
The two new APIs for Google Maps, Tracks and Geolocation, are targeted at the over 800,000 developers who are already using the Maps APIs to create their own apps.
The Google Maps Tracks API lets you build apps that can store, display and analyze GPS data on a map. It includes support for a technique called geo-fencing, where a user can create a virtual region on a map to notify a device when it enters or exits a predefined area.
For example, the Google blog suggests a fleet management company could set up notifications that would automatically alert drivers whenever they were 10 miles outside their delivery territory and need to turn around.
The Geolocation API allows you to create apps that can work out their own location without the use of GPS by looking up the locations of nearby wifi access points and cell towers. This means the app is less tough on battery life as the GPS usage is limited, and the app can work indoors or in remote areas.
While the status of the Tracks API is "experimental" which, means that its use is currently unrestricted, in the case of the Geolocation API you need an API key before you can use it. While you may use a free quota of 100 requests per day for testing and development you still need to obtain a Maps API for Business license and activate billing before you can use it for real.