Beyond Compare - Beyond Compare allows you to compare files and folders.
Prey - Prey is the simplest and most reliable solution for tracking, data protection & management for Windows, Mac, and mobile devices. Track with precise location, wipe, reset and secure devices across all platforms.
WinMerge - WinMerge is an open source differencing and merging tool for Windows.
Android Lost - Remotely control your Android phone from the internet or by SMS. Features:
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.
iLostFinder - iLostFinder is an anti-theft/lost app for iPhone and iPad.