The #flipclass, pretesting and differentiation

This is my first year starting the #flipclass from the beginning. I started mid-year last year and am grateful to have a name to describe it and the support of knowing I'm not the only one doing it. <--(Thanks to @jonbergmann and others for laying the groundwork!)
I teach Geometry if you haven't read my previous posts. The class can typically be a class that catches math students off guard. The most successful math student in previous courses can stumble initially on the need heavy focus on reasoning and spatial visualization (although we should probably focus on this in all math courses).
For "homework" last night students had to watch 5 videos (all 5 minutes or less) and take notes on a provided accompanying sheet. (I actual had a student say "yes!" when they heard what the homework assignment was for the night.)
When students came to class today I had prepared a 4 question clicker activity to sort the kids in the room based on the understanding they had after viewing the videos. I was very pleased with the scores on the questions and ended up being able to work with 3 struggling students fairly closely for the last 30 minutes of class. At the end of class the students had a better grasp of the core idea of the lesson.
I am so excited for the possibilities the #flipclass can bring in differentiating instruction and making it more individualized for each student's needs.
It was amazing to sit back at times and see the varied activity about the room (submitting homework electronically, working on additional practice, having MATH conversations with their peers, watching videos again on ipods and asking questions as they have them). I believe this to be the future of education and my role as a teacher and facilitator.