santaku - Reply in 3 Taps
Tap one of three AI replies
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Reply in just three taps. santaku offers three ready-made replies—pick one and the chat keeps flowing. Now the options fit your relationship even better.
Stop agonizing over how to reply.
santaku is a messenger with a simple twist: replies are mostly three taps. When a message arrives, AI reads the flow of your conversation and prepares three ways you could respond. You just tap one—and the chat moves forward.
No more time spent typing. No more time spent overthinking.
— Rally in threes
When someone sends a free-text message, the person receiving it sees three reply options. Tap one and those words are sent as your reply.
The person who receives it then sees three options of their own. Back and forth you go—three taps at a time—until either of you chooses to type freely again.
— Choose your tone
The three options are written to match the tone you prefer:
• Positive / Neutral / Negative
• Warm / Casual / Formal
• Agree / Ask / Close
Switch anytime in settings to fit your mood or who you're talking to.
— Free text, always
Three taps take the lead, but your own words are never more than a tap away. Tap "write my own" whenever you want to say something in your own voice. The three choices are for ease; free text is for feeling. Both are yours.
— Built to feel safe
• Block and report anyone who bothers you
• Inappropriate words are filtered before a message is ever sent
• Reported content is reviewed and acted on by our team
• By default, you only exchange messages with people you mutually follow (adjustable in settings)
— Japanese and English
The app follows your device language automatically, and you can switch anytime in settings.
The lowest possible bar to reply.
santaku makes conversation effortless.
From plan8 Inc. (Yufu, Oita, Japan)
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
• Set each chat's relationship, tone, and nickname so the three replies fit even better
• AI now writes your "persona" from your past messages (you can edit it anytime)
• Your partner's icon adapts to the relationship and the mood of the chat
• Refreshed visual design with a new translucent "glass" look
• Minor improvements and stability fixes
The developer, HIDEAKI TSURUOKA, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Contact Info
- User Content
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- HIDEAKI TSURUOKA
- Size
- 31.1 MB
- Category
- Social Networking
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
16+
- 16+
- Contains
Messaging and Chat
User-Generated Content
- Copyright
- © 2026 plan8 inc.