Just checked out Seal. My impression:

It uses the same backend as MeTube (yt-dlp), so they have the same capability as far as website support and file formats.

Seal looks like a good option if you don’t have access to your home network or if you don’t have a dedicated machine to host things.

I still prefer MeTube because it’s a web UI that I can access from any machine. I use a VPN to stay connected to my house so I could still use MeTube while away.

Is it primarily for iPhone users?

MeTube is just a web UI, not a phone app. It is accessible by any device that can see the local IP and port of the host machine.

Yeah, that’s about it. You can watch it directly in the browser as well.

MeTube, for when my friends send me a video on a service I don’t use (facebook, instagram, tiktok). It supports a lot of sites.