ALLCAST APP NOT SHOWING UP! Please help!

I recently downloaded the AllCast app to stream to my TV from my iphone. The app downloads but does not show up in my applications under my phone anywhere and I am unable to use it. Anyone else having this issue?? I have messaged the developers of the app a bunch of times and they have not responded with help. I am using an iphone 10 on the newest OS too. Thank you!

-M