This is a simple iOS (and Mac Catalyst) application to demonstrate use of the sfomuseum/swifter-protomaps package.
It bundles a Protomaps tile database for the San Francisco International Airport (SFO, launches an instance of the httpswifter/swifter HTTP server running on localhost:9001 that will serve requests for those tiles and displays a single ViewController that loads a web application for displaying the tiles.
For a longer version detailing why we did this please see the Serving map tiles to yourself using Protomaps and iOS blog post.
The httpswifter/swifter HTTP server, and handlers for serving Protomaps tiles, is started in the applications AppDelegate code.
The web application is instantiated in the application's main ViewController code.
The web application itself is contain in the application's www.bundle package and makes requests for tiles to the local HTTP server.