Educreations is one of the top contenders, teachers say, mostly because of its simple user interface and multi-functionality. "I use it when I need to make quick videos in class," said Ramsey Musallam, a high school chemistry teacher in San Francisco. Other features that teachers seem to love: the app offers more than one page for recording; the user can import images from other places and format them easily within the video; there's a text feature so students don't have to contend with messy teacher handwriting, and perhaps best of all, it can be used on desktop computers, not just an iPad.