On Sunday, August 9, 2020 at 3:07:01 PM UTC+1, wrote:
Please is there any gadget/circuit/App that can detect a mobile phone when ;
1. even when the phone is off but the battery is inside.
2. When the phone is on
3. when the battery has been removed
thank you.

Thanks to you all. My next problem is after detection, can the phone be zeroed in on? (located)