This is a attempt for macOS app development in Swift to provide a app skeleton for my future app dev, with several goals:

• Minimal Cocoa app startup code without using compiler synthesized main function by @UIApplicationMain.
• Not using any storyboard and xib/nib files, all UI element is programmatically created.
• Not using any AutoLayout, all layout functions is implemented manually for efficiency purpose.
• This app contains a basic function to downlaod from web using async URLSession api.