I built Jabcode Studio, a tool for creating and scanning high-density QR-like 2D colour barcodes. Unlike standard QR codes, these use multiple colours to pack much more data (upwards of 2 KB per code).
Web and iOS available. App store link here: https://apps.apple.com/ca/app/jabcode-studio/id6749924342
JAB Code has been around for a while, with some discussion here a few years ago: https://news.ycombinator.com/item?id=18495250
But this is the first implementation I've seen for files (without compiling from source) and the first iOS compatibility I’ve seen.