Every other writing app has learned to write. It finishes your sentences, offers “better” ones, studies your voice, then hands the work back with the life pressed out of it. Clive never writes for you. It reads over your shoulder instead: the grammar slip, the word you've echoed too close, the filler you lean on. It tells you, then gets out of the way. Nothing leaves your machine. No model has read a line of your book.
What it does. Grammar and spelling. The words you've echoed too close together, the filter phrases (“she felt,” “he saw”) that hold a reader at arm's length, the dialogue adverbs, the sentence that has quietly run too long. It tells you. You decide.
What it won't do. Finish your sentence, generate the next one, “improve” your tone, or send a word of it anywhere. No model has read your book. None ever will.