YTunnel Pro is not freeware software. You can download and use it if you have to buy it first. Its arround 15$. Personally, YTunnel is almost like Yahoo Ace (free)or YTK (Lite for Free), with little more advanced features.
Y!TunnelPro is a feature rich, easy-to-use program that integrates with and enhances Yahoo! Messenger. The following list contains only a handful of the features includes in Y!TunnelPro. Features: Enhanced Chatroom Userlist, Multi-Messenger, Simplified Chat User Verification, Voice "Keep-Alive", Enhanced Privacy, Chatroom Enhancements, Unlimited friends list, Unlimited ignore list, Font and Effects Filtering, Advanced Filtering, Advanced SPAM Filtering, "Live User" verification.