im using sloth trader
only limitations so far...
it can't look further back than 24hours (so if someones site goes down for a day you might mistake them as a bad trade
Also, you can only have 1 URL for return hits and a track URL. So this means things like Toplists, that send you traffic from a subdomain but need you to send traffic to the main domain don't work (like Joes Traffic)
Other than that, its good.
If there was one that had the simplicity of Sloth Trader but fixed those features I'd be well impressed.
Oh and sloth is a browser based install. Upload the php file and then access it in ya browser
