I learned of this ironically from Krishna De over in a Google+ post. I can't find any mention on Twitter's blog or website.
You get to it by going into the iOS app, tapping on "Me" in the lower right corner and then on the gear icon in the top middle to get into your Settings. You then have "QR Code" as an option:
I did try the "QR Scanner" button on the "QR Code" page and it works pretty much exactly like the equivalent function in Snapchat and Facebook. When I pointed it at Krishna's QR code in her G+ post (as displayed on my Mac's screen), the app showed me her profile and let me know I was already following her:
So it works.
But I share the same question Krishna has in her G+ post: WHY is Twitter doing this?
I'm not really sure why I would promote this as a way to have people connect to me. Twitter already has the "@" mentions such as "@danyork" that easily allows people to connect to my page. It's not entirely clear to my why this is needed.
Perhaps Twitter sees this as a way to help people more easily connect. From the "QR Code" page I have the ability to tweet the photo of "Share via..." and send it through other means.
But given that the QR Scanner is buried through several levels (Main page -> Me -> Settings -> QR Code -> QR Scanner) I don't see this really being any easier than simply typing in the person's user name in the app - or sending someone the URL for my Twitter profile.
I thought about the physical printing of one of these QR codes as a way for people to get to my account, but again, with the current level of steps you need to go through it seems to be more work than most people are going to want to do.
Perhaps this is just a case, as Krishna wonders, of Twitter wanting to keep up with Facebook and Snapchat. They all have codes, so Twitter needs a code.
Or maybe this a preview of features yet to come.
What do you think? What value (if any) do you see in these kind of QR codes? Would you use it?