With the release of iOS 13 and macOS 10.15, Apple has combined the Find Friends and Find My Phone apps into one utility. The latter turns all apple gadgets into a kind of Bluetooth beacons, allowing you to find a lost or stolen device even if it is not connected to a mobile or Wi-Fi network.
This innovation was made possible by the use of Bluetooth Low Energy technology, which requires so little energy that it can send signals from a fully discharged device for another one to two months. This signal is picked up by other iPhones or iPads that are next to the lost gadget.
However, there is one caveat in all this. In order to find a lost Apple gadget, the user must have on hand another Apple device tied to the same account. This is the only way to decipher the location of a missing iPhone, iPad or MacBook. To keep user information confidential, the missing device sends out an ever-changing key.