looking at this diagram suggests that in app purchasing requires that I have an application server.
I don't have an application server for this project, can I use Amazon In App purchases? Mainly asking if anyone has experience with this, and how they developed a solution
Technically you don't have to check the receipt, but then you are vulnerable to users faking a purchase in various ways.
The green lines are all marked as optional according to the diagram. So only steps 1-5 are truly required, and none of those need your own server.