Great Job Agnes with all the details you have put in your article.
For the Scan it option i feel the design can be further simplified by removing the capture screen in between.
Also why will we really need a view history tag on the scan screen.
That can be accessed from past orders as well if someone wants to re-order/ view related products to something already ordered in past. May be i am missing something here. Looking forward to hear more about it from you.