EdPuzzle is one of my favorite tools for Flipped learning. It allows teachers to hold students accountable for watching a video and thinking while they watch. You can embed questions throughout the video for students to answer. It will store the answers for you and grade the multiple choice questions.
Below is a video I made for my Curriculum, Instruction, and Assessment class as a preview for how it works.
Instructional specialist/coach, Google Certified Trainer, Level 1 and 2 Google Certified educator, Ed Tech Team Teacher Leader Certified, growing and learning