Two approaches to seeing installed fonts

Fonts.swift

import UIKit
import PlaygroundSupport

// Print fonts
extension UIFont {
    public static func printAllFonts() {
        for family in UIFont.familyNames.sorted() {
            let names = UIFont.fontNames(forFamilyName: family)
            print("Family: \(family)")
            names.forEach {
                print("- " + $0)
            }
            print("~~~~~~")
        }
    }
}

UIFont.printAllFonts()

// Font Picker Controller
let config = UIFontPickerViewController.Configuration()
config.includeFaces = true
let fontPickerViewController = UIFontPickerViewController(configuration: config)
PlaygroundPage.current.liveView = fontPickerViewController