YouTube sermon videos work great in our church app. There are a few things you'll want to make sure you do to get the videos to display correctly and not get the dreaded "Video unavailable" screen:
If you're seeing this in your app, then go through the following list:
1) Ensure you have checked the "Allow embedding" box on the video from within your YouTube account.
2) Ensure you have not restricted the video from playing on your website or app. More information is here.
Once you take care of these items, your video will load as expected. Happy viewing!