You could remove this if you wanted but that would require a change in the styling of the app. If you need more info on how to style, look the below how to:

https://docs.mendix.com/howto/front-end/customize-styling-new

This is really a feature you would see in all the Mendix apps and can be really handy if the screen is huge. I would suggest to check if you really want to remove this.