Well, I've seen the latest video of their platform and yes it is so simple to understand because we/you have the choice of what you want to do with the change. This is the link where I've seen the video
https://www.youtube.com/watch?v=QJxjZKIDxXA.
I've seen the usability of their POS. It's easy to use and no hassle when it comes to transactions. Is the all in the video already working or just an prototype?
Seems like it's a working prototype one, you can download it directly from the YouTube and hope you can enjoy the platform without issues.