just like 'Grammarly' which is basically just a keylogger
But yeah i tested grammarly for 5 minutes and found it crazy.
there has to be a better way getting both worlds :|
As an alternative there is LanguageTool which you can install locally. We have it running on a small VM that people can configure their installs to talk to, and block the public service end-point (as sending to that would be a big no-no for us for the same reason as Grammarly). It doesn't have all the features of Grammarly so isn't a complete drop-in replacement, but the self-hosted version works as well as the free features of Grammarly.
I'm surprised that Grammarly hasn't come up with a local service like that, I bet they have a ton of enterprise users that would appreciate it.