Snooping Apps

OpenSignal app icon

Is both an Android and iPhone app.
Uses crowd sourced data to show signal coverage of cellular carriers.  What folks do is to run the app when you are out and about. The OpenSIgnal collects signal quality for your carrier.  The data is sent to  The results are showing back to you. I encourage you to run the app. Small cell towers have been installed on utility poles along Darnestown Road and Dufief Mill road.  Our coverage should have improved.  Let's find out.

  You can look at crowd source coverage in a web browser
Identifies what cell tower you are using. The plus signs with the small circle in the middle are the cell towers.  Your location is identified by the blue dot. The large blue circle with the tower symbol in the middle is the tower that your phone is connected to.  Signal strength ranges to  -44 dBm to -140dBm.   -44 dBm is the best.  -140dBm. is the worst. [ Don't ask me why the number are this way. Makes for interesting graphs. ] Note: In the Signal graph -113 is the better signal strength.  Thus the signal strength is that good.  I got one bar.  The bars you see on your phone are not standardized between carriers and I assume phones.

What tower is used for you cell phone conversation is a complex question, but it can be several miles away.  I read that the maximum cell phone range is 32 miles.  You will not connect to towers this far away in an urban area.  You cell phone seeks out the best signal.  Usually, you connect to the closes tower.  What I see on my Android phone using the Sprint network.

Cell Map -- Map with nearest tower

Using your Android phone as a signal meter on a Sprint network.

Cell Map -- Signal Meter

Coverage Map
   Coverage Map
Is an Android App.

coverage data from Coverage Map android app

"signal checker lite"
Is on the Android.
Displays numbers.
Carrier signal strength information

*3001#12345#*  Will connect you to a local number so you can check signal strength and see what cell tower you are on. I do not believe this will work when you are connected via wifi.