Right Here

Locate your phone by text with a secret message, authorize four phones to request your location, send your location by text/email, periodically. Find your lost phone by triggering a nasty beep. (locate ur own phone from another trusted phone, email urself). Optimal power usage. Read more at http://www.interopware.com

Recent changes:
v2.0.1 - fixed a bug where beep feature worked only when location-by-text was also enabled.
v2.0.0 - added audio/beep feature to find lost phone.
v1.0.0 - find phones GPS location by secret-msg from trusted phones