For educational purposes only--use at your own risk, not endorsed by Salesforce, your mileage may vary, no lifeguard on duty, produced in a facility containing peanuts and wheat, safe Harbor, etc.
Get the phone app I'm using https://scan.me/download
Code for creating QR code image formula fields https://gist.github.com/mshanemc/57cfb289fd8b52152a54
Video demo here: https://youtu.be/foQ_5sYoHp0
Code walkthrough here: https://youtu.be/dvjX_m8oyR8
But I just want it as a package!
https://login.salesforce.com/packaging/installPackage.apexp?p0=04t61000000MYT8