I've been writing tutorials and making videos for the Ray Wenderlich website for a few years now. Here they are in list form:
Written
Siri Shortcuts Tutorial in iOS 12
Video Streaming Tutorial for iOS: Getting Started
How to Make a UIViewController Transition Animation Like in the Ping App
Real-Time Communication with Streams
Swift JSON Tutorial: Working with JSON
AsyncDisplayKit: Automatic Layout
AsyncDisplayKit: Getting Started
State Restoration: Getting Started
Video Courses