Diary
Log what you're having
Start with the barcode. If it's already known this is one tap; if it isn't, your photos become the product — for your diary and for everyone who scans it after you.
What are you having?
Start with the barcode. If we already know the product it takes one tap; if nobody has it yet, you'll be the one who opens it.
Without a code it stays in your diary only. There is nowhere shared to keep a product that has no way of being found again.