Great that you can edit panels in a web browser and view those panels on any device. I would like to make a suggestion that when editing in a desktop web browser an option is provided to set the screen size you are editing so that the tiles maintain the same order and sequence as they would on the device that Action Tiles will be displayed on. Perhaps something like 2048 x 1536 pixels for an Ipad Air being displayed in Landscape mode. No need to have a list of every screen size - just let user enter pixel height and width.
Customer support service by UserEcho