PEAR - Connecting newsletters and advertisers 🍐
Teech - 24/7 Unlimited help from the world's best students
Revue - The easiest way to create and send a curated newsletter
BrainAround - Q&A site for college textbook problems & solutions
Buttondown - Buttondown is the best way to start and run your newsletter
ofCourseBooks - Let your students write, save and share their course notes.