New sign-ups are currently open to phone numbers in the United States, Taiwan, and the European Economic Area. If you see "Checkmate isn't open in your country yet", you can join the waitlist to be notified when it opens. The app, calls, and emails are available in English, German, French, Spanish (Spain and Latin America), Japanese, Korean, Simplified Chinese, and Traditional Chinese. Your language is locked while you have an active goal, so choose it before creating one.