But, Apple recently patented new technology that will find your lost iPhone even when switched off.
But, hold on, Apple finally has a solution for this.
How the system works?

Apple may put a timer to periodically connect a part of the machine from an off state.
They would send the location codes via-mail or text message.
It is not clear if the feature would work on iPads and MacBooks using Wi-Fi only.

There are various systems that communicate in both directions and which can be improved.

