What are you running on the tiny's?
2 things primarily
* Plex HTPC Client (works much better than the Vizio app)
* A custom web app I made for displaying what's playing whatever's streaming from my MPD server (90% of the day podcasts, 10% music)
More recently I've been displaying a MagicMirror dashboard I whipped up too. There's also a websocket server I created, runs on each of the Tiny's, which accepts commands from a web/phone app I made. In addition to allowing control of the TVs via websockets, it also switches between the plex client, magicmirror and the custom mpd client display screens.
Within the MPD display client, there are 3 distinct screens. 1 is a Vue app running Milkdrop visuals. The other are 2 screens I coded up.
This one is a full screen Vue app that displays realtime "spectrum analyzer". Yes I know it's not a real spectrum analyzer, but most non-audio technophiles would indeed call this display a spectrum analyzer. It's runs full screen on the 65 inch TVs and is actually really cool looking, whether the MPD server is streaming podcasts or music. The websocket server, also running on each Tiny, allows me to turn on/off different parts of the display like progress bar, the frequency bars, clock, artist, title and so on.
I also have a version of this one, which is used for my vinyl turntable. It doesn't have artist, title and progress bar since it strictly listens to analog line-in on the audio card.

The other is not a Vue app, but just a simple web app I coded up. It also runs full screen and displays/plays audio of the MPD livestream. If you couldn't tell what I was going for, it's kind of a reel-to-reel tape simulator with cover art in the middle, working VU meters, spectrum analyzer and info display on the bottom. It also looks really cool fullscreen on the 65 inch displays. The 3D rendered parts I made in Blender and the frequency bar display logic is borrowed from the other view above. The info display on the lower right is an generated SVG image rendered 30fps. This one was quite a challenge to work out how to make the tape display on the reels show the actual time elapsed/remaining correctly.
You can see it in action here, obviously not the live streaming app itself, but the reel-to-reel visualization rendered:
Reel To Reel Audio Visualizer
I think it looks pretty cool, others would call it a waste of CPU resources, power and time.