Brilliant.org provides interactive activities for students to learn math, engineering, and computer science. These activities are organized into "courses" that are named for practical interests, fields, and professions—such as casino probability, beautiful geometry, applied probability, and search engines. Centered on exploration and practicality, the company holds three core ideals: curiosity-first, freedom to fail, and active learning.
Although it costs money (aside from a free trial), this can be a site that the playbook or toolbelt can point to. It's also another project with similar ideals to Plot Twisters.