For iOS I’ve been using iSH. It’s on GitHub (and the AppStore) and is an Alpine Linux shell for iOS. It provides no creature comforts for managing SSH connections, but does drop you into a pretty standard Linux shell. I believe it’s a stock Alpine install. iSH is an interesting project in and of itself, but in this context, you can also install a standard openssh client. This is usually as much support as I need on my phone or iPad to connect to a remote server.
ish looks quite good. I was using blink shell, until they switched and I didn’t notice in time to get grandfathered in. But I’m beginning to wonder if ish would have been a better pick in the first place (although, I don’t have a use for ssh on iOS beyond what Panic Prompt provides anymore, anyway).
I liked blink shell and panic prompt. In particular blink shell seemed very Linux-familiar. I switched back to a laptop a bit ago, though (iPad+ssh was a pandemic era fix that ended up surprisingly nice, but I can’t bring my desktop to do ssh over lan, if I want to go to a cafe or something).
"secure shellfish" has some support for images, movies, etc. I'm not sure what they're using for transfer. If you ask it to, it installs ".shellfishrc" which adds a "quicklook" shell command.
It also has some integration with the "files" app to transfer files in and out of your shell session.
Edit: and I've got a cron job checking on a web site that will send a notification if has changed to my watch via the secure shellfish "notify" command.
https://github.com/ish-app/ish