How I Use It
The best part of BrainPop is they have worksheets for notes and extension activities that correlate with the lessons. I used it when we had a little unexpected down time, had a substitute, or they just needed a "brain break", but not really as a main lesson. I also used it as a whole-class reward or a website where they could enjoy some self-directed learning. They like that the characters are consistent and found the videos very entertaining. I'm not sure they would learn from the videos themselves because the pacing tends to be a bit quick, but it's a helpful, different reinforcement for concepts they've already learned.
This website is hit or miss. If they have a video that addresses exactly what you're teaching, it's great. If not, they can sometimes be tangential. Be sure to watch the whole video! Sometimes the videos will go beyond a concept or address it below the level they should.
It's a great place for kids to go on and tinker their own, either as a reward or when they've completed work.