If you swipe from the left side of the screen on Fully Kiosk Browser, the menu for Fully Kiosk Browser should appear allowing you to change the Fully Kiosk Browser configuration.
My recommendation would be to design the dashboard on the device that is most comfortable to you. Typically, most people like to develop their dashboards on a computer as it’s easier to create their different resources (media, hyperlinks, etc), drag-and-drop tiles, etc.
What’s cool is if you already have your Fire HD opened with your desired dashboard loaded, then as you make changes on your computer and press the orange save icon, those changes will immediately be pushed to your tablet and displayed immediately.
The following post has some tips on designing from a computer - specifically how you can use the Chrome Developer Tools to mimic a specific screen size:
There isn’t a way to turn off the layout reflow, but it shouldn’t completely rearrange your tiles when you press save. As you move tiles around, the system will automatically try to push existing tiles down to maintain their horizontal position. And if there are any gaps left when you save a dashboard it will automatically close those gaps (shifting tiles so they flow left-to-right, top-to-bottom), so using a Blank Spacer Tile from the Other category:
