Is Termius the only cross platform emulator that includes Android as one of the platforms? It is quite good, in my limited experience, but too expensive for a hobbiest. I like that I can use my Linux desktop, MacOS laptop, and Android tablet/phone and the UX is the same across them all. The sync (trial for free, then charge) is great. But I'd be fine if it was something where I could DIY a sync method with something like Syncthing.
I'm aware of the likes of Alacritty, but no mobile app. And of course Termux is great for mobile, but no desktop versions.
It all boils down to wanting some sort of sync function either DIY or otherwise that includes hosts and SSH keys and while not as important, I do like the consistent UX between platforms. Is there something else to consider?
You can have a virtual terminal program to run text-based programs on the local system. On Linux, alacritty, xterm, urxvt, kitty, gnome-terminal, konsole, and the Linux kernel's native virtual terminals all can do this. They have nothing to do with remote communication. They're just pretending to be a traditional (non-virtual) terminal, something like this. You used to plug a bunch of those dumb terminals directly into a single (extremely expensive) computer to let many people share it. Those are pretty much gone, but we still provide virtual terminal software that emulates it. It deals with stuff like scrolling text on the window and colorizing it.
Inside those terminal emulators, you can run text-based programs. One text-based program that you might run is a text-based ssh client, like OpenSSH. That'll deal with securely connecting to another host over the Internet, authenticating, and encrypting data between the two.
You can also have a single software package that provides both a terminal emulator and an ssh client, which is more-common on, say, Windows. PuTTY is an example of this. ConnectBot on Android.
I think that all the platforms I know of provide some way of doing both the separate terminal emulator program/text-based ssh client and the combined model. Windows, Linux, Android, MacOS. But historically, Unix has had a considerably-nicer text-based environment than Windows, so I suspect that more users on Windows use combined ssh/virtual terminal programs, because they're rarely using text-based programs on their local system.
Thank you, that helps clear it up. I was certainly conflating the two previously. This makes sense now.