As well as Nibbler there were a number of US based (and somewhat better funded) options coming onto the market. As is the case with many startups SiteMorph suffered from not having a long enough runway. While some investors showed interest the meetings inevitably ended with discussions about "acquiring XYZ more customers, then we can talk". This was great advice though ultimately exit velocity wasn't achieved.
Along the way I did learn a huge amount about startups, business operations, marketing and sales.
If you are looking for a website testing technology here is a list of other options:
More to come.