So many tools in this category are racing toward autonomy. Read the inbox, write the reply, send it, tell you afterwards. The pitch is always fewer decisions for you.
Every other AI writes what you tell it. Ghostwriter writes what you already know. Double-tap Left Ctrl in any text field, in any app, and the reply is there — drawn from the thread on screen, your calendar, your files and your past meetings, indexed in an encrypted vault on your PC. It won't double-book you, and it matches how you write to that person, down to the sign-off. Then it stops: it types into the box and never sends. Windows.