They have [an IzzyOnDroid app](https://apt.izzysoft.de/fdroid/index/apk/dev.kuylar.lighttube) in early development.
edit: Here are the instances that are up at the moment:
https://tube.kuylar.dev/
https://tube.dsezer.dev/
https://tube.inftord.tech/
https://lighttube.wardpearce.com/
They say the videos are proxied in the github’s readme. Your IP should be safe.