I'm a retired network engineer. Since retiring I've been writing Swift applications for MacOS and iOS as an independent developer. Most of these are applications useful for network engineers:

1. Etherdump: Packet capture and analysis tool
2. Network Mom ACL Analyzer: Analyzes Cisco ACLs
3. Network Mom Availability: Monitors devices and reports availability metrics
4. Netrek: A reimplementation of the classic internet game using Swift and SpriteKit (open-sourced)

Binaries for all three are in the MacOS 10.14 Mojave App Store. Etherdump and Netrek sources are public in my GitHub repository.