Neovim Is a highly customizable, modal text editor program. Probably no what you’re looking for as far as terninal emulators go, but I use it daily as a near-IDE on desktop. Look into LazyVim for an easy way to get started.
I can second KDE connect–use it between my phone and Manjaro. Can’t speak to the other applications because I don’t have a use-case for many of their functions on a smart phone myself.
I’m glad to see this is still around: https://exercism.org/
helped me learn when I was starting out 7-8 years ago