Startup Idea : gps acount

i have an idea about gps maps, in my gps maps idea every body has its acount and can share his location for every body that its identifying acount is his number, and by using this condition u can find your friend so easy, and this apps can sync by sites which has an office any where and by sharing its location in sites and syncing by gps u can navigate so easy to the location and u dont need to dialing to his office. i appologize for bad english typing.