Verizon locks some of their BlackBerry phones' GPS. If you have one of those models, you need a bluetooth external GPS receiver to work with our app. Our app works well with external GPS, but we CANNOT make your phone's built-in GPS work. Actually your phone's GPS won't work with any GPS apps except those from Verizon and you pay a monthly fee. It is an issue between you and Verizon, there is nothing that BlackBerry App World or MTT can do to change that.