A software for display the users status on Yahoo (Online - Offline - Invisible).
Editor: Here are some key features of Yahoo Invisible Detector:

路 View and Save the users avatar
路 Ability to Send PM to the checked ID
路 Ability to display the user profile in Yahoo or Yahoo 360
路 Ability to Call the checked ID
路 Ability to add ID to buddy list in Yahoo Messenger
路 With a lot of new Yahoo Messenger Emoticons
路 Appropriate speed to display users status
路 Ability to the last checked IDs (with date and time)
路 With 39 new emoticons for Yahoo Messenger
路 Ability to auto send emoticons to Yahoo Messenger chat window
路 Ability to check for new versions. you can free download Yahoo Invisible Detector 1.0 now.