Casey Newton, the Verge:
Before now, to follow someone on Twitter you had to click a giant button that said “Follow” at the top of their profile. Ugh, no thanks! Now, following someone is as easy as navigating to your profile, tapping the gear icon, tapping “QR code,” tapping the blue button to open the scanner, and scanning your friend’s QR code, assuming they have also navigated to their own profile and excavated the QR code and physically handed their device to you.
QR stands for “quick response” — not exactly an apt description for adding barcodes to an app in 2016.