Vote and thank you later

There are apps like Glympse and Family Locator that allow you to continuously publish your location (kind of like the map of available taxi drivers on the Uber app). There are also security apps that allow you to find your device if it is lost or stolen. Obviously, the app must be installed in order to use it.

He leido varias respuesta y creo que lo que andas buscando es un servicio online, que puedes realizarlo desde cualquier móvil, sin necesidad de descargar nada y en unos 5 minutos obtienes la ubicación del celular que quieres rastrear, para ello entras en la web de Rastrear un celular y escribes el prefijo y el celular que quieres rastrear y tras cargar 2 o 3 minutos se abre en mapa con la ubicación del celular que has rastreado.

I see no one has answered the simplest way.

Not without access to the internet and access to the relevant cellular network and/or via GPS.

In other words, to track an Att will require access to the Att network and also that the service is available for use by the public.