Love the plug-in! Just what I was looking for. It should be ranked higher in WordPress, as the higher ranked tooltip plug-ins aren’t nearly as good as yours!
I have a little experience in programming, thus was able to figure-out (with a little digging), that the title class needs to be added. Perhaps under “Installation” you might want to consider adding the final steps: select enable for all links, add title attribute with tooltip content where you want the tooltip to appear. (What about images? Haven’t tried any yet, but might be useful)
Anyways, great work here. Keep it up!
Johnathan