Paste a draft. Yubook scores it against X's published ranking signals before it goes out: reply, share, or mute. Then it ranks fresh posts from accounts you follow, so a reply can still land in front of someone else's readers. No follow-for-follow. Does not post to X for you. You get a seven-day plan, a watch list from accounts you follow, follower tracking, AI rewrites, and Threads when you press publish. Free: search-visibility check and best hours. Korean & English. $7.9/week or $69.9/year.