Android Apps for GSM signal analysisGSM Field Test 
Logs signal strength and geolocation viewable live as a big fat line of dots on a google map. Logs are downloadable as kml files.
Network Signal Info 
Shows GSM dBm or WIFI strength on a meter and shows info on cell tower locations, your IMSI and other details about your phone and network. Also logs info downloadable as kml files. Template:-
Web based tools
Open Cell ID 
GSM Signal strength heatmaps, base station locations, API and Android app.