Buddy Spy 2.2.19 Publisher's Description

Buddy Spy allows you to keep track of what other Yahoo Messenger! users are doing, even if they are in Invisible or Stealth Mode. The program shows if the user is online, what chat room they are in (if any) and if their web cam is online.
It is able to do this by connecting to Yahoo! Messenger's servers and using its YMSG protocol. Sending carefully crafted packets, and listening to their responses. Buddy Spy's Feature list include,

Stealth Checking
Room Checking
Webcam Checking
Improved GUI
More Custom Settings
More Packet Types