Yes to use their service I need to send them text, they can't process it if I don't although it would be nice if they offered an offline app, even at a price.

However it's annoying how they store documents and try to be a document management / basic authoring system to, I see no reason why they should need to store documents.

It also seems they are missing a trick. If Grammarly opened up their API's, there are so many integrations that people can freely write and drive more paying Grammarly customers. At the moment I copy and paste from my text editor into Grammarly and back out! I never installed the browser extension for the same reasons the originally twitter poster mentioned, i selectively copy and paste in to the app.