Hi,
My suggestion would be to have different wireframes for Web and Native apps and always go for vertical alignment not harizontal . The mendix native UI is customizable in all aspects. Few tweeks in the properties will make the UI shine better. For example for the above screenshot make the data view as a vertical aligned one and use the properties to add spacing between the buttons. One other way is that you can define a complete UI package with the codes from here. Also, checkout these webinars on native styling here.
Because usually there are fewer pixels to work with. Native apps tend to have only 640x480 px.
Btw, the text 'Page title’ will also show up in the app if you use Atlas_UI's Layout 'NativePhone_TopBarOnly’