I wish there was something like repl.it but with an even more basic UI (but which still allowed saving and sharing of programs). Super-beginners don't need version control or a debugger, and I worry that extra visual noise draws away brain power when you're starting out.

We use Trinket.io at my Girls Who Code club (or did before Coronavirus mayhem shut it down). It has the simpler interface, but one huge flaw—the free version is some kind of weird hybrid interpreter that will attempt to run both python 2 and python 3 code (in the same program, even).