Difficulty: Moderate
Platform: Web, iOS, Android, YouTube Extension
Price: Free for individual teachers. School pricing available for more features.
Flipped Learning
Difficulty: Moderate
Platform: Web via Chrome extension
Price: Free for limited use; price plans for individual teachers and schools available.
Difficulty: Moderate
Platform: Web
Price: Free for basic use. Master Instructor accounts add extra features (need to create a free account to view pricing)
Difficulty: Easy
Platform: Web
Price: Free trial; unlimited and institution-wide plans available.