LanguageTool also belongs to an American company, because it was acquired by Learneo in 2023. You can also see this on the LanugaTool website. If you click on Imprint, you will see a German company, but if you go to the terms and conditions, it suddenly becomes an American company.

And it works great for my languages. I really like it.

Just tried it. Kind of awful for swedish, try “dem slår de”.