Edpuzzle.com has been around for awhile but I think it has been overlooked by many and deserves its time in the sun.
At my school time is very precious because we are running two programs at the same time (a Korea curriculum and our English one) so our teacher have to do more with less!
A great way to do this is using a flipped classroom where the students are tasked with watching a video before a certain class so they can be pre-loaded with the basics. This allows not only for the teacher to save time but also for the students to feel prepared for what they will be doing that day.
A perfect tool for this is www.EDPUZZLE.com