Thanks @majd!
As far as dimensions go, if your app looks good in a mobile browser, it will look the same using our service. I’d recommend using Bubble’s responsive builder or using the Chrome console (Command + Option + I when previewing your app on Mac) to test how your app looks on different mobile screen sizes. That will give you an idea of how your app will look.
You can also use our preview app to see how your app would look as a native app. You don’t have to purchase the plugin to view your app inside of our preview app, just to implement the native features.
As far as other best practices, here’s something I mentioned recently on single-page vs multi-page applications: Best practices for mobile app implementation?
For menus, I’ve typically seen people either use Bubble’s built-in Slidebar Menu, or have a “Tab Bar” menu at the bottom of the screen. For the latter, you could have a floating group at the bottom of the screen with other groups inside of it for navigation. Tab menus tend to work better on single-page native applications, instead of multi-page.
Hope that helps! Let me know if you have any other questions!