This seems like an unreal tool, 5mins of free screencasting per screencast. Add your own images and record your voice over the top in what is an amazingly easy and quick process. Log in by using a Google, Twitter, Facebook or Yahoo account. If you don't have one of these quickly create a Google account by Googling 'create Google account' (will take 5 mins for someone who thinks they have no idea about these things!).
I can see all sorts of applications for using Screenr from junior primary to senior secondary. Ideas could include:
