I wanted to use this from my Macbook Pro specifically to watch training videos I had on a bigger screen. It does not work. When I try to start them from the application, the AirPlayMirror Receiver just sits there waiting for a connection. Since this is my primary use case, I was very disappointed.
On the flip side, just doing the airplay from my MacBook Pro (to show the desktop) does work properly. You can't then play a video in this mode, mind you, because it can't keep up properly. I had been using a free mirror application for the main use case, and it would work for one video and then I hard to restart it (so that is why I bought this). Buy not always > Free.
I have been using this app on FireTV Stick for about a month. It works well with my iPhone XR and iPad Air2. noth pf which are on iOS13. Before buying this app, i had used free trial app "AirPlayMirror Receiver (Demo)" which worked for 15 minutes each time. As i was satisfied with the free demo app, i decided to buy full version app, and it works flawlessly. Nice way to try before buy. Happy Mirroring!!