The quickest and easiest way to build an app for Macs depends on your specific needs and your level of programming expertise. Here are a few options to consider:

  1. Apple's SwiftUI: If you want to build a native macOS app and you're relatively new to app development, SwiftUI is a great choice. It's a user interface toolkit provided by Apple, and it's designed to be easy to learn and use. You can create macOS apps using SwiftUI in Xcode, Apple's integrated development environment.
  2. Xcode: Xcode is Apple's official IDE for macOS app development. It includes all the tools you need to design, code, and test your app. You can use Swift, Apple's programming language, or Objective-C to write macOS apps in Xcode.
  3. App Builders and Low-Code Platforms: If you're not a developer and want a simple way to create a basic app, you can explore low-code or no-code platforms like Apple's own Swift Playgrounds for iPad or other third-party tools. These platforms often provide drag-and-drop interfaces for designing apps and might have templates for macOS apps.
  4. Web Apps: If your app doesn't require access to macOS-specific features and can run in a web browser, you can create a web app using HTML, CSS, and JavaScript. This can be a quick way to reach macOS users, but it won't provide the same level of integration with the OS as a native app.
  5. Cross-Platform Development Tools: If you want to target multiple platforms, including macOS, you can consider using cross-platform development frameworks like Flutter (Dart) or Electron (JavaScript/HTML/CSS). These frameworks allow you to write code once and deploy it on multiple platforms, including Mac.
  6. Mac Catalyst: If you already have an iOS app, you can use Mac Catalyst to bring it to macOS with relatively little additional effort. Mac Catalyst allows you to adapt your iPad app for the Mac.

The choice of the quickest and easiest method depends on your specific requirements, existing skills, and the complexity of the app you want to build. If you're new to macOS app development, starting with SwiftUI and Xcode is a good way to learn and build native apps for Macs.