Simple Spy 

---------- V 1.2.4 ----------
Updated to work with 5.4.X
Increased default time between alerts to 60 seconds
Enabled compatability for MoP
Will automatically hide when entering an arena or FFA area, such as in Nagrand.
Added shaman prowl obtained from symbiosis.
Will alert you when an ally is killed by an enemy player.

---------- V 1.2.3 ----------
More efficient
Fixed missing text in frame
Now properly scales with the rest of your ui
Now properly hides with cinematics

---------- V 1.2.2 ----------
Fixed a few possible localization bugs

---------- V 1.2.1 ----------
Fixed bug with it showing in sanctuaries
Fixed bug where it would show in the middle of a cinematic
Reduced the likelihood of any conflicts with other addons
Got rid of some clutter in the code

---------- V 1.2.0 ----------
Prints a message when someone stealths, camo's, vanishes, etc.
Should be usable on MoP beta, just need to fix a few bugs to enable all the features like cross realm players in questing zones.
Improved efficiency.
It should now properly hide when in a battleground.
Included a timestamp when it finds someone.
Added two new slash commands
- '/ss stealth' which will enable/disable the printing of when people go invisible.
- '/ss reset' which will move the frame to the center of the screen and reset the list of people.

---------- V 1.1.0 ----------
Will now alert you with a short beep.
Added slash command to change alert refresh times.

---------- V 1.0.0 ----------
Initial Release