Firstly, I came to know about this forum and website because I was watching Flo in his topic " Introduction to WidgetKit in SwiftUI - The Compilation Video". Great job, Flo. You explained very clearly. I have a feedback which is to slow down a bit as I was following your codes by doing it in Xcode myself 
Secondly, I downloaded the sample code from GitHub. I followed your course until Lesson 2 where you ran it in a Simulator to show the widgets. My build compile fine and the app runs but not the widget. I see this error message:
“The request to open “com.apple.springboard” failed.” UserInfo={NSLocalizedFailureReason=The request was denied by service delegate (SBMainWorkspace).,
I have checked the signing and it was fine… so I am at lost as to what would be the reason for not being able to see the widgets in the simulator. Thank you in advance.