I'm looking to build a very lightweight learning management system of sorts. I'll have 2 custom post types "Course" and "Lesson". I will associate the Lessons to the Courses, probably by using the Advanced Custom Fields plugin.
What I need to do is somehow track whether or not a user has "completed" or "viewed" a specific Lesson. I'll probably add a button that says "Mark as Complete" or something.
The question is, what information should I be saving, and how should I be saving it (when the user clicks the button)? Further, what table in the DB should this information be saved in?
I see that there are some plugins out there like WP Complete, but it doesn't offer exactly what I need. I'm open to any ideas/recommendations. Thanks!