Google recruits its users to improve indoor location accuracy

At the time you could use it to traverse places like airports, shopping centers and even your local IKEA, but navigating indoor spaces overall has remained relatively limited, something Google are attempting to rectify.
The Google Maps Floor Plan Marker app for Android is the digital cartography solution the developers at Google Inc. have managed to come up with.
Although stating in its description, “Likely to be of interest, mostly to map enthusiasts and venue owners,” the app isn’t strictly speaking off limits to any users, but it does require you upload a floor plan prior to using the app, which can then track your device’s movements within the confines of the structure you’ve allocated basing location data not just on your device’s GPS, but local cell tower and WiFi network positioning. The app can even tell which floor you’re on.
The idea being that with more user-generated indoor mapping being carried out, the native functionality of this feature within the standard Google Maps app will go way up. Users won’t just be able to find the lighting section in their local IKEA, but perhaps the right book hiding on a shelf of their local book store.
The app itself will run on phones or tablets running Android 2.3 and up, so if fancy contributing to the service, everyone will benefit. If you want to submit a floor plan to get started you can head too.