I already have done all the work for this. I have 2 different models. A small version and a large version. Unfortunately they do not work. I used a designed from someone on here and as you can see, I have had bad luck.
PLEASE be confident in your low voltage skills.... Components as small as 0201 and know about bluetooth 4.0 chips. I am using nrf8002.
I have all the Gerber files and data sheets and board files that you will need to complete the work.
Basically it is a bluetooth tracker that connects to a phone. You can make it beep or light up with an LED.