Okay, someone tell me if this device exists (or build it!). I want a device where I can pay $10-15 to get a gadget in the mail. The gadget would sit in my pocket for a week wherever I go. The device would record cell phone signal strength for each of the four major U.S. carriers every few seconds. After a week or so, the device would deliver the verdict on which cell phone carrier would have the strongest signal for me. Then I could mail the device back so someone else could use it — sort of a Netflix-like model to temporarily borrow this device.

At any point, I could go to a web page to view a map of where I’d been. The page would show a “heat map” of signal strength for each carrier or frequency band. Maybe I could also slice/dice by time or see the total number of readings in each location. I’m pretty sure you could rig this up out of 2-3 cell phones running Android in the worst case.

So far, I’ve found:

Android

- RF Signal Tracker is a nice app to collect and map signal strength data. It looks like it can upload to OpenCellID, which is a project to create an open database of cell IDs (numbers that correspond to cells).
- Antennas is a pretty cool free app to show you nearby antennas and signal strength. It can even export some data in KML for use with Google Maps/Earth, but it doesn’t seem to make a heat map that could be easily grokked.
- Sensorly has a free Android app, but they seem to want you to pay to zoom in closer than city level. I’m willing to do that, but didn’t see the for-pay addon in the Android Market.

iPhone

- I also found an iPhone app called Signals that will continuously collect signal data and upload it.
- AT&T offers an iPhone app called Mark the Spot to report dropped calls, no coverage, etc. I have to admit that I don’t understand why this is manual though. Personally, I’d want my phone to ping my carrier with its location every time the phone dropped a call.

Web

- SignalMap is a website to (manually!) submit the number of bars for a location. It doesn’t appear to have any mobile app to back it up. Likewise, Dead Cell Zones and Got Reception? appear to rely on manual reports. I don’t think manual reports is the best way to tackle cell phone coverage maps though — you really want an app for this.
- http://www.cellreception.com/ has the standard manual reports data, but also will map the location of cell phone towers based on the location of cell phone towers registered with the FCC.
- Root Wireless powers the cell phone signal strength maps that CNET uses, but I didn’t see any apps I could download or install on a phone. I registered to be a beta tester a long time ago, but no one ever contacted me.

That’s what I could find. Do you know of any good Android (or iPhone) programs to collect, map, or upload cell phone strength measurements? If so, let me know in the comments.