There's a similar system here in Switzerland, called Twint. It is run by a group of banks though, and I don't know if the central bank is involved. Each bank issues its own App. It had a slow start, but suddenly got a lot of traction, and nowadays you can pay literally everywhere with it. Online shops, regular shops, restaurants, the bars in the stadium of your favorite football club.
Person to person payment is also possible.
You can also easily create a QR code if you set up a stand at a flea market or something like that, but it's not necessary, since all you need is the cell phone number of the recipient.
Everybody with a cell phone is using it, even my grandma. It's a huge success.
It works like a regular bank transfer between bank accounts. The banks get no information about what was paid with it, only the amount and from where to whom.
The only downside: The banks set fees according to the market, so it's in competition with bank transfers, but also with credit cards like Visa and Master, or Paypal. It's still possible to pay very small amounts of cash like CHF 2.- or 3.- though.
Recently, I had a walk with my kid and we walked past a stand where kids sold self made popcorn and cookies. They asked 1.- per piece, and they accepted Twint. I bought some things and paid by Twint to the cell phone number of the kids dad they gave me. :)