I found the Q&A about delaying the tabGroup.open() by using the setTimeout() function. My problem, though, is that it seems like none of my code in my primary window is being processed while the default screen is displayed. So the app isn't ready no matter how long I set the timeout for. Does anyone have an idea for how to accomplish this?
I don't think you can have code in other window's processed while the default screen is shown. However, I would expect you could run code in the main app.js. Doesn't that work?
Open a first window that only display the same image as Default.png, maybe with a loading indicator to show the user something is happening.
After your app is loaded get rid of this window.