You're right, it's an interpreter and that would be the 100% accurate term.

For online coding environments, the two are often used interchangeably. More people search for 'compiler', so I'm using that widely on my site.

Honestly: It makes it sound like you literally have no idea what you're talking about. Not a good look for someone trying to sell a service.

Those who actually want to produce binaries from their Python scripts, which this doesn't do.

Many of this services use “compiler” in their description. It may be technically true if they use Python implementation that compiles Python source to byte code first, and then interprets the resulting bytecode (like CPython, Pypy implementation do).