I often wonder if T-Mobile uses other sources to verify their network coverage. We all know about Open Signal, Rootmetrics, Sensorly, and Ookla and how everybody uses them to prove their speed or coverage over another carrier.

Obviously those are company products and cellmapper is a developers app, but with such a large crowd sourced database of information does T-Mobile take a look at anything like that be it officially or unofficially?

For instance I've used the app most everywhere I go on a regular basis at least several times to build a pattern. I have found many areas where I had good to great signal where the T-Mobile coverage maps say I should have none. Obviously this is a much more accurate description of the network and we also know that the coverage maps are generally outdated and not very accurate along the outside borders of proposed coverage.

CellMapper has really helped me prove to naysayers that coverage in some rural areas is actually much better than they thought because they were going on the information from T-Mobile official coverage maps.