When FireMonkey introduced the FireUI Preview a few releases back, the application was available in the Google and Apple stores, to simplify the deployment to a device. The same app is also a demo available as source code, but that requires a few configuration steps to be able to compile and deploy to a device. Having a prebuilt ready-to-use version is a nice advantage.
Now Embarcadero has published again the FireUI App Preview application on the Google Play Store, at https://play.google.com/store/apps/details?id=com.embarcadero.fireuiapppreview
Once this is installed on your device, you need to enable the View | Broadcast to devices feature of the RAD Studio IDE, open a FireMonkey form, and from the app, connect to the IDE on the PC listed (notice this requires both the PC or VM running the IDE and the device to be on the same internal network):
Now if you open a form in the designer in the IDE, like the following:
You'll immediately see it on the device in the FireUI App Preview, with the proper style, and any change you make to the form at design time will be immediately reflected on the device preview:
Of course, if you open a project with a more complete UI, like the Accelerometer demo, you'll see it showing on your device, before compiling and deploying it:
This helps significantly cutting on the time it takes to design the UI of an app and see it on an actual device, reducing the development time significantly. In this area FireMonkey offers a much better experience than most of the other multi device development tools out there!