While there might be some value in educational materials and keyword tool, this CANNOT be called WordPress plugin. Here is why:
1. When you install it all it does it gives you username and password and a bunch of external links. This means all functionality is offsite. You can actually use this for any site, it doesn't have to be WordPress, you just need to know URL address to their online dashboard.
Why to use up your resources to install something that doesn't do anything anyway?
2. The trial itself is limited. You can read instruction manual only till stage 3. You don't get complete version for 14 days.
3. You can read their forums but you can't ask any questions or post replies. Quite useless.
If their keyword numbers work that would be awesome, however their choice of marketing strategy makes me suspicious. It looks like author simply used this as a way to market to WordPress community. Calling this a plugin is very close to deception. You have a great product? Great! But you should market it properly and call things what they are.