Meet the Pairable KEY: a smart device you can attach to your valuable items to keep track of them. With the Pairable app, you can ring your key to find the item it is attached to. The KEY also lets you control your phone and IFTTT devices. The device also can serve as a motion detector. It alerts you when someone has moved your things. There is even a built-in temperature sensor.
The device is powered by a replaceable CR2032 coin cell battery. It has a working range of 100 feet. Sets you back under $40.