I Found It iFi Smart Tag

The I Found It iFi Smart Tag™ and iPhone (iPhone 4S, 5, 5s, iPad 3, 4 and iPad Mini) connect over Bluetooth like a wireless leash and keep track of each other. Simply attach the Tag to keys, purse, or your very personal tool box. From your phone you can page the tag or just press the button on the tag to page your phone. Multiple tags can be attached to one phone… it means you can track your keys, purse, lap top and other valuables and even loved ones from your iPhone.