On Kickstarter, there is a campaign for a RFID tag of sorts. It works with Bluetooth LE and is powered by energy harvesting the 2.4 gigahertz band. With clear line of site, they claim a range of 200 feet.
The product is called iFind and the company is WeTag.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.