Cell phone track application, gps or internet following.

Cell Phone following, tracking codes. I have two cell phones. One is samsung galaxy s3 and the other is samsung galaxy s5. Two phone have internet and GPS on them. I want to track with one to other. I want to find where is other phone, while I use a application. I need source codes. I will be improve the codes after given source codes. When I left a phone at home or other where, I want to find where is the phone? I use android studio as a developer program. I have no time to develep this code. So I decided to find a develeper to help me.