The free version of iFly says it's up to 10 users, yet when I'm working on my site and have multiple windows open, it stops loading. I only had 7 pages open that had chat visible (I have it set to no chat on admin pages), no one else was on the site, and still it stopped connecting. I tested it again, and if there is more than 7 windows open, eighth will say "Loading" and get stuck on that. Then, if I refresh pages seven and six, they will be stuck on "Loading", too. Only if I close three windows will the last three start working again.
Also, in the plugin description is says we can embed the chat, yet apparently this is a pro feature? Then why does it list this as a possible in the WordPress.org plugin description?