For the people who hate the telephone simulator in the app settings of the Homey developer page.
Here the chrome css, tested with stylebot extension for the transformation into a tablet 
https://developer.athom.com/tools/app-settings
/* Make all elements invisible to hide the simulator selector */
.Page.PageToolsSettings {
visibility: hidden;
}
/* But still show the phone itself and flexible resize and realign */
.Page.PageToolsSettings .Simulator {
visibility: visible;
width: 150%;
margin-left: -50%;
}
/* Finetune the layout of the screen */
.Page.PageToolsSettings .Simulator .SimulatorInner {
width: 98%;
margin-left: 1%;
margin-right: 1%;
}
/* Now the phone is a tablet :) */
