# Si4iMsg

> Si4iMsg (iPhone/iPad app by 文焕 陈.)

- Source: https://appshunter.io/ios/app/si4imsg/id6820102972 (this page in markdown: same URL + `.md`)
- Developer: [文焕 陈](https://appshunter.io/developer/1810161184)
- Category: Social Networking
- Price: Free
- Age rating: 4+
- Requires: iOS 18.2 · 3 MB
- Languages: English, French, German, Japanese, Korean, Chinese, Spanish
- Released: 2026-10-16
- Data updated: 2026-10-20

## What is Si4iMsg?

Si4iMsg turns an iMessage into a capsule. When your friend taps it, the message opens with a reveal effect: fireworks, a thunderstorm, falling cherry blossoms, a stomping T. rex, or the animal of the Chinese zodiac with a New Year greeting. Turn on end-to-end encryption, and only your devices and your friend's can read it.

Everything happens in Messages. There is no account and no sign-up.

REVEAL EFFECTS
• Basic: fireworks, lightning, scratch card, typewriter and flip card
• Weather: wind, rain, thunderstorm, snow, fog, sunshine, rainbow, sandstorm, typhoon and aurora
• Plants: cherry blossom, rose, sunflower, bamboo, maple leaves, dandelion, tree and four-leaf clover
• Dinosaurs: T. rex, brachiosaurus, pterosaur, raptors, a dinosaur egg, a volcano, a fossil to brush free, a fire dragon and a water dragon
• Chinese zodiac: all twelve animals, each with its own entrance, plus a greeting you pick or write yourself
Effects play on your friend's device and follow Reduce Motion and VoiceOver.

END-TO-END ENCRYPTION, WHEN YOU WANT IT
• Off at first, so you can start right away. Turn it on for a conversation with one tap.
• You and your friend swap public keys once, inside the conversation.
• Each device has its own private key, made in its Secure Enclave. It never leaves the device and is never backed up.
• Every message is encrypted on your device for each of your friend's devices and each of yours (HPKE with P-256, AES-GCM).
• Compare a key code in person or on a call to be sure you have the right key.

READ-ONCE AND EXPIRING CAPSULES
• A read-once capsule opens once, then it is gone.
• Capsules can expire after a time you choose.

HOW CAPSULES TRAVEL
Si4iMsg uploads each capsule to a relay server and sends a short link as the iMessage bubble. For an encrypted capsule the relay only ever gets ciphertext. You can add your own relay, or choose "No relay" to carry a short capsule inside the link itself. Capsules without encryption, and every capsule in a group chat, reach the relay as plain text. The readable copies stay on your devices.

GOOD TO KNOW
• Your friend needs Si4iMsg to open capsules and see the effects.
• Group conversations send capsules without encryption.
• In English, Simplified Chinese, Japanese, German, Korean, Spanish and French.

No ads. No tracking.

## Is Si4iMsg safe?

Not enough ratings yet to assess Si4iMsg.

## Is Si4iMsg legit?

Si4iMsg has limited verification signals. The AppsHunter Legitimacy Score for Si4iMsg is 48 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 1 release)

### 1.0 — 2026-10-16

No release notes.

## More apps by 文焕 陈

- [Si4Keyboard](https://appshunter.io/ios/app/si4keyboard/id6745263713)
- [Si4iLocker](https://appshunter.io/ios/app/si4ilocker/id6747120411)

All apps by 文焕 陈: https://appshunter.io/developer/1810161184

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-20.*