Within the last weeks I did prepare a completely new help and tutorial page for all our TabShop users, which can be found here:
https://tabshop.smartlab.at/help.html
The help page is focused on how to solve typical Point of Sale (POS) related use-cases within TabShop. Examples are how to define your own product stock lists, how to checkout and print an invoice and how to change the appearance of your TabShop Android Point of Sale system.
The help page will grow in terms of content over the next couple of weeks and cover more and more use-cases for mobile cashiers.