Monitors GSM network cell availability / RF signal strength, and displays a map of approximate antenna locations.
A red circle indicates the cell site that your mobile phone is currently using. If your GPS is turned off, this will most likely coinside with your reported location.
Yellow circles indicate other cell sites in your vicinity, that your mobile receiver is able to connect to. Note that only the sites for your current network provider are visible to the application.
Smaller yellow circles indicate other cell sites in your vicinity that your mobile receiver was able to connect earlier in this session, but are now out of reach.
Blue circles indicate user location as reported by the GPS (G), the Google Network Location service (N) or as best guessed based on nearby antenna locations (A).
The numbers in the circles indicate signal strength. To calculate dBm from the number shown, use the formula dBm = -113 + 2 * strength. Values below -112 dBm are shown as 0, values over -52 dBm are shown as 31. If signal strength is unknown, a "?" is shown.
Pan and zoom are available (just touch the map). To return to your location and/or switch to satellite view, hit the MENU button
There is also a status line with the active antenna Location Area Code and Cell ID.
Turn Autocenter On/Off: When enabled, the map will always recenter at the current location.
Use Sat/Map View: Choose a map or satellite photo view of the map.
Location Setting: Shortcut to permit each enabling of the GPS.
Scan/Don't Scan in Background: Scanning when application is in background allows you to collect and cache more antenna locations, but will consume more battery.
Compass: Display a compass indicator on the screen. Rotate the phone until the needle points up. The accuracy of the compass depends on the accuracy of the phone's mag sensors. Please calibrate the compass using any of the specialized compass tools available for Android.
About: Display version info and IMEI.
Location data is often unavailable or erroneous. Interesting discussion on this issue on Slashdot
In theory, leaving your phone running with the GPS on will eventually allow Google to collect more data for your area which will improve the database. In theory.
Data for 3G cells is especially sparse and unreliable. For best results, set the phone to "2G Only", and use the GPS to get an accurate fix for your own location.
In any case, antenna locations are only approximate. In actual use, some antenna locations are accurate to a few meters, while others a hundred of meters away from the location shown.
The idea is that this app can help you understand the GSM infastructure in your neighborhood, compare providers (if you have multiple SIMs to test with), and perhaps even get a better signal in certain areas. Of course, you need to have at least some connectivity in order to use it, so it is likely to not work when you most need it. Still, it was an interesting little app to write.
v0.81: Compass option + bug fixes (thanks: Jacob and Piotr). See web page for details.
User reports: Works great in some areas; in others, less so or not at all. Best in 2G mode; limited functionality in 3G.
Antennas free for your Android phone