Screen casting/mirroring/streaming

How would I add a casting/screen mirroring to my mobile app?It's a static screen with a countdown timer.

Hello Juanita. I have an app called Screen Stream Mirroring:

I do have the paid version, and it saved me on quite a few demos already, when I needed to showcase an app to a large audience. The great thing about this app is that you can connect to it via a browser, provided that the device and the browser are in the same network.

The app does have a free version, but I'm not sure what the limitations are.