Endpoint:
isp.thx.dog
Returns:
{"success":true,"ip":"216.73.216.13","isp":"Amazon.com"}

Endpoint:
isp.thx.dog?callback=func
Returns:
func({"success":true,"ip":"216.73.216.13","isp":"Amazon.com"});

Endpoint:
isp.thx.dog/xx.xx.xx.xx
Returns:
func({"success":true,"ip":"xx.xx.xx.xx","isp":"ISP Name Here"});

Endpoint:
isp.thx.dog/xx.xx.xx.xx?callback=func
Returns:
func({"success":true,"ip":"xx.xx.xx.xx","isp":"ISP Name Here"});