One of my very favourite Chrome Extensions is Screencastify. It’s super simple for students to use and by using magic (and drive integration… but mostly magic) it automatically uploads your screencast videos straight into your Google Drive.
We use this tool in loads of different ways including students explaining about something they have created, recording tutorials and them using it as a thinking out loud tool. We always see great motivation from students when screencasting as it is a genre of video on youtube that they watch exhaustively at home.
For iPads the new built in recording in iOS 11 will be handy, but when a student is on a Chromebook, Mac or using Windows then screencastify is really hard to beat for convenience. We push this app out for auto-installation on all our Chromebooks.
General workflow is to then submit screencasts to teachers using Google Classroom. Videos are recorded in the webm format, which is good but not so useful if you want to use the video in other ways. To get around this we use another awesome Chrome app called Cloud Convert that will happily take your webm and give you back an mp4.
The barrier to entry on this one is really low. It works on any computer running Chrome. Check it out for a great way of students showing their learning.