Suggestion of UML diagram

I need to draw a diagram but I am not sure what sort of diagram that is appropriate for my application.

It is a mobile application that contains:

1. Splash (as welcoming scree)


2. Main Menu Screen (Which contains)
   
   
   
   • Gallery
   
   
   • Settings
   
   
   • Map
   
   
   • Help
   
   

The Gallery has contain all the images/photos that is stored on the device.

Can anyone suggest what sort of UML that is appropriate for this application? Is it Use Case Diagram? or Sequence Diagram?

Thanks in advance.

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