Using active surveillance applications may interfere with your system's Antivirus and/or Security protection. Download.com cannot guarantee the security of surveillance software because of their nature.
Plug Spy is a first grade tool to observe your Mac. It activates automatically on screen lock and triggers actions in case of unexpected occurrences. Instant notification on you phone will give you additional security if you leave your Mac alone. Plug-Spy is living in the OS X system menu, ready to observe your Mac. Select one of the Action-Sets and you are done. Plug-Spy will activate it's sensors on screen lock and trigger actions based on predefined rules. Action-Sets are based on sensors, user-defined rules and resulting activities. No matter if you want to know who is waking your Mac or entering a wrong password in your absence, Plug-Spy can trigger actions dependent on your requirements.
Sensors currently available are observing the MagSafe adapter, computer power-state, connected screens and login window. Any sensor activity can result in an alert sound, iSight snapshot, local notification, a Boxcar, Pushover or Pushbullet message to your phone, or a post on Twitter.