I don't use Instagram so I can't compare. I don't use the Amazon mobile app either. What I do know is that the Amazon mobile website, while ugly and outdated i

I don't use Instagram so I can't compare. I don't use the Amazon mobile app either. What I do know is that the Amazon mobile website, while ugly and outdated in many respects, runs ways better in my crap Android phone than probably 99% of SPAs. I don't know, but it's probable the "Instragram in-app shopping experience" has better UX. Although that's not really what we're discussing here, are we?