Syncbox: Couple App
Private SNS for two
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Syncbox is a private space for just two people - a couple, or two close friends.
It is not a social feed built to be seen. It is a box where letters and conversations that reach only each other pile up, one by one. The quiet wait for a letter that might be there, the flutter of opening it - all of it becomes your story together.
◆ Made for
· Couples who hate watching chat messages scroll away and disappear
· Partners who exchange letters on anniversaries but have nowhere to keep them
· Two people in a long-distance relationship who want to send their hearts more carefully
· Best friends who live far apart but still want to share everyday life
◆ Weekly letter
Once a week, write a letter with real care. Attach photos and a song. You can unsend it as long as it has not been read.
◆ Q&A (two-way questions)
Answer questions like "When did you first fall for each other?" Both answers are revealed only once you have both written yours. A new question each time, to know each other a little deeper.
◆ Piece letter
It does not have to be a long letter. Send a small piece of your heart the moment it comes to mind, and trade replies.
◆ Feed
Share today's moment with one photo and a caption. Emoji reactions and comments keep the conversation going lightly.
◆ DM (real-time chat)
A messenger for just the two of you: quoted replies, emoji reactions, photos, videos and voice messages, chat search and jump-to-date. Star the messages you want to keep.
◆ Bookmarks
Gather the letter lines, photos and chat moments you want to treasure in one place - your shared keepsake box.
◆ Privacy you can count on
· Strictly 1:1 - connected only to the one person you invite
· App lock with a PIN and Face ID / Touch ID
· Notification emails never include the message body
· All data travels over encrypted connections only
Time passes, but what you shared can stay.
Start keeping your story in Syncbox today.
A Closer Look
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
- Unread DM and letter counts now show on the app icon.
- The close and save buttons in the photo viewer now respond properly.
- Fixed a leftover character when sending several messages in a row.
- Minor bug fixes.
The developer, Jiyoon Yeo, 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
- Diagnostics
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- User Content
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Jiyoon Yeo
- Size
- 11.3 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPod touch
Requires iOS 15.0 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
- Korean
- Age Rating
4+
- 4+
- Contains
Messaging and Chat
User-Generated Content
- Copyright
- © 2026 여지윤