I been wanting to put our Visionati api to work, but needed it to intergrate with WordPress. We developed our own WordPress plugin, I have to say it's lightning fast, so VisionATI backend is up to the task. We find all images in the media library with no description, have roles setup to meet the description type, automatic description option to all new uploads.
Plus we created a second plugin to find all posts that have images with no alt tags and to add the alt tag found in the media library. Again impressed with VisionATI backend speed and happy to get to use it.
