I'm Rob Dixon.
I develop apps for iPhone/iPad and Mac, using Xcode, Swift, and Objective-C.
This site illustrates some of the techniques that I've used in my apps.
XML, Firebase, JSON, CSV, HTML, Barcodes/QR-Codes
Bluetooth 4.0/LE, UDP Broadcast, Multipeer Connectivity
Apple Maps, Google Maps, MapBox, OpenStreetMap
Portfolio on Freelancer, apps, on the App Store and in development.