MTI Map tool
Yes, even thou I dont always trust it! sometimes I get customers who claim they get dropped calls, I go to MTi tool, enter their zip code and according to the map they should'nt had been able to use their phone at all!!! due to no coverage whatsoever, so I think that map tool is not up to date, besides this I find it very useful
I love it.
Even if it shows "no coverage" in areas where coveratge is provided only by roaming.
Looking up an place in Maine, for instance, is quite alarming. ("What do you mean, the whole state is white?")