What is the best iphone OBD 2 Scan Tool?

I am looking to see what members here think is the best scan tool hardware and app that integrates into an iphone. Viewing readiness monitors is a must.

Hmm I use dash command and an elm device but I haven’t found one that does readiness monitors

Does it have to be iphone? I’ve got this and it’s fairly inexpensive scans codes and readiness monitors among giving you data on a host of other things.

http://www.ultra-gauge.com/ultragauge/index.htm

I think Torque for Android does it all, but, not out for iPhone.

Rev