There are a dizzying variety of BT locators on the market and available for pre-ordering. They have widely varying design goals, and some seem to work much better than others.
This site provides an overview of 15 or so of the available models, and the PebbleBee is highly rated:
http://www.codehaven.co.uk/chipolo-vs-lapa-vs-tile/
CodebenderIts not so highly rated by Play store users where is only has 2.3 stars with a lot of complaints about crashes (as does their Kickstarter page). Maybe the iOS version is better, but as an Android user I'm hesitant to buy in at this point given how recent the complaints are.
This site provides an overview of 15 or so of the available models, and the PebbleBee is highly rated:
http://www.codehaven.co.uk/chipolo-vs-lapa-vs-tile/