Can I Use TestFlight Beta Testing for Apps Not Created Using Xcode? I just submitted my enrollment application to be an Apple Developer. 

I have three Mac 3D Puzzle apps that were created using Unity 5.3.2 that I plan to sign and submit to the Mac App Store after I'm approved as an Apple Developer. I have .app executable files created, not Xcode projects.

I'm new to Xcode. I'm currently taking the iOS Development in Swift course by Plymouth University recommended by Apple. When you create a new Xcode project one of the options is OS X which I'm thinking is for creating Mac apps. I assume the course will cover uploading apps to the iTunes App Store.

On other platforms such as Amazon and the Windows App Store their websites specifically mention that apps submitted will be tested before they are approved. I did not find anything about submitted apps being tested other than the documentation on the What's Included link about the TestFlight Beta Testing program. The text on this link mentions testing for iOS and tvOS apps. When you click the Learn more link it mentions iOS, watchOS and tvOS, not Mac.

The documentation says on the page that displays after Clicking Learn more: "To get your app ready for testers, upload a beta build of your app from Xcode and add the names and email address of people that you’d like to test in iTunes Connect." Is the TestFlight Beta Testing program only for testing apps that are written using Xcode?
No, is not necessary. You can upload your app from both Xcode or Application Loader.


  Application Loader is a tool to help you upload your apps to iTunes
  Connect. It’s particularly helpful if your app includes In-App
  Purchase products that need to be configured for the app. Application
  Loader is explained in Using Application Loader. Application Loader is
  available from the Resources and Help section of iTunes Connect.


With that tool you will be able to upload your .ipa file. Once your app is upload, you can distribute that build over Test Flight.