Sketch - Professional digital design for Mac.
Kaywa QR Code - Kaywa QR Code is a QR-Code Generator.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
ZXing Project QR Code Generator - Generate QR Codes.
Affinity Designer - Professional creative software, exclusively for Mac.
Scanova.io - QR code generator, designer, and campaign management tool.