It's open source too, according to the description, it streams and doesn't cache videos and apparently it handles 4K HDR. If data usage is a concern to you, be aware that some videos are close to 1 GB.
I use this one on my TV, and it's great, highly recommend.
If bandwidth is a concern, you can also point it towards a local JSON file with whatever URLs you want, so you can mirror the screensavers locally and then stream them from there.
No guarantees from me that it's any good : https://play.google.com/store/apps/details?id=com.codingbuff...
It's open source too, according to the description, it streams and doesn't cache videos and apparently it handles 4K HDR. If data usage is a concern to you, be aware that some videos are close to 1 GB.