Are there any *truly Intelligent Tutoring Systems (ITS) available for public use?

[Defined](https://en.wikipedia.org/wiki/Intelligent_tutoring_system) as:
"a computer system that aims to provide immediate and customized instruction or feedback to learners, usually without requiring intervention from a human teacher."

Keep in mind that a passive progress meter or a proficiency model does not qualify as an ITS.

artificial intelligent public systems tutoring