How to structure project with initial progress view? Infinite loop of top of stack.

I'm developing my first app, and the flow of views has led me to become confused. 

My app is quite basic. It just makes a few API calls and displays data about a football match. 

I was having difficulties with loading content, my API call was taking too long to return the data so I force a 5 second progress loop on the user which is just a progress indicator view with a 5 second timer. The user is then presented with the main menu (press menu button to continue). When they do so, the fetched data is displayed fine. 

The problem happens when the user wants to exit the application. Since the top view is a progress indicator, it's essentially impossible to back out of as the user. I want the flow to look something like this:

1. App launches

2. Loading screen for 5 seconds

3. Main menu 

4. Data menus

When the user is done, I want the reverse order to be something like:

Data menus > Main Menu > exit application.

I have found a solution for this which is simply calling the System.exit() function in the onBack of the main menu delegate, however I think this is bad practice and instead want to know how I should be achieving this?

Happy to provide code, sorry if this question has been asked I couldn't find anything similar in the forum.