Cogito were very prompt and clear in the annotation services they offer and delivered on their promises at a reasonable price point. They delivered a complex annotation in a very short time frame, and were very responsive, when I disagreed with the annotation in a small number of cases. I would use them again for similar annotation tasks. Review collected by and hosted on G2.com.
Cogito use v7labs.com, which is a popular platform for image annotation. However I found this web platform to be a little restricting. For example I downloaded the whole annotation and viewed it off-line as I found this much easier to assess the annotation. A small issue. Review collected by and hosted on G2.com.