Suchi — Pure. Private. Forever.

Suchı

Pure. Private. Forever.

End-to-end encrypted messaging and calling built on the Signal protocol, with post-quantum key exchange. No accounts, no phone numbers, no cloud copies — and a server that keeps no names, not even for us.

⬇ Download for Android Completely free — no card, no account · Android 7.0+ · installs directly · iPhone version in the works 🍎

🎬 See the new features — 32 seconds

🚫 Silent block — they never know · ⏸️ Pause mode — you simply look offline · 📩 Message requests — read first, then decide.

🧮 The calculator & your PIN

First time you open Suchi, you see an ordinary calculator. Type any 4–6 digit number and press = — that number becomes your secret PIN, and your private vault is created. That PIN is the only "account" you will ever make.
Every time after, Suchi still looks like a calculator — because it is one. It really adds, subtracts, multiplies. Type your PIN and press = to step inside your chats.
A wrong number just shows "Error" — like any calculator would. There is no lock screen, no login page, no hint that an app is even there. 🔒
Your PIN is never stored as numbers. Only its mathematical fingerprint (a salted hash) is kept — nobody can recover it, not even us. Choose it well and keep it in your head.
Fingerprint or face can open it too — Suchi offers it automatically once your PIN exists. Dismissed the prompt? Tap the little 🔓 at the bottom of the calculator and it comes back.

📲 How to install

Tap Download above and open the Suchi.apk file.
Android will ask to allow installs from your browser — tap Allow (one time). This is normal for apps shared outside the Play Store.
Tap Install, then open Suchi and set your PIN on the calculator (above).
If a 🔋 battery tip appears at the top of your chat list, follow it once: Settings → Apps → Suchi → Battery → Unrestricted, and allow notifications. That's what makes the phone always ring, even locked in your pocket.

💬 First chat in 30 seconds

Unlock the calculator with your PIN and press =.
Your Suchi ID is in your contact list (🆔) — tap to copy, send it to a friend any way you like.
Type their ID in the add-a-friend box beside the Suchi name, tap ➕, pick them from 👥 — and say hi. Photos, videos, voice notes and 😊 emojis all work.
To call, open the chat and tap 📞 or 🎥 — encrypted end to end, and it rings even when their app is closed.
For maximum trust, meet in person and compare safety numbers — tap ▼ → 🛡. Matching numbers prove nobody is in the middle.

🎛 The ▼ menu — your control panel

👥
Contacts
Your people — pick a chat, copy your own 🆔 Suchi ID, or add a friend by theirs.
👨‍👩‍👧
New group
Gather several Suchi IDs into one encrypted room — every member gets their own encryption.
⏸️
Pause mode
One tap and Suchi goes completely quiet — no messages arrive, no calls ring; to everyone else you simply look offline. Tap ▶️ Resume and everything waiting reaches you at once. A live call is never interrupted — pause waits until it ends.
🚫
Blocked
Every ID you've silenced lives here — unblock with one tap. Blocking is silent: their messages are dropped before they're even decrypted, their calls never ring, and they are never told.
🛡
Verify keys
Compare safety numbers with the open chat — in person is best. Orange means not verified yet, teal means the encryption is proven. If a key ever changes, Suchi warns you.
💣
Self-destruct timer
Messages erase themselves 5, 10 or 30 seconds after being opened — or leave it Off and they stay.
⏱
Auto-lock timer
Choose Right away, or give yourself a 1, 5 or 10 minute grace period before the calculator lock comes back. Teal means a timer is set.
🔆
Screen on in calls
Stops the screen from sleeping while you talk. Teal means on.
🧨
Panic wipe
Asks once, then destroys PIN, keys, ID, contacts, chat history and the vault key — permanently and forensically. Use only when you mean it.

🔒 The instant-lock button lives in the chat header — one tap locks Suchi on the spot, no matter what timer is set.

🔐 What's inside

Signal-protocol encryptionEvery message and call sealed on your phone — even our server can't read or hear it.

⚛️ Post-quantum key exchangeKyber-1024 protects the first handshake — built to stay secret even against the computers of tomorrow.

📞 Calls that always ringEncrypted voice and video — rings even when the app is closed and the phone is locked, and keeps ringing until they answer.

👨‍👩‍👧‍👦 Group voice & video callsSmall rooms of 3–4 people — everyone connected to everyone, all encrypted. Open a group chat and tap 📹 in the top corner.

🚫 Silent blockBlock any ID — they are never told. Their messages are dropped before your phone even decrypts them, and their calls never ring.

⏸️ Pause modePause the whole app: chats and calls wait quietly until you tap Resume — then everything arrives at once. You simply look offline.

📩 Message requestsA message from an unsaved ID never sneaks into your chats. A notice at the top lets you read it first — then add, reply, delete or block.

🤏 Minimize the callDrop the call to a floating pill and read or answer your messages — while you keep talking.

✋ Your video, your wayIn a video call your own picture floats in the corner — drag it anywhere on screen, or tap it to swap big/small.

🖼 Profile picturesGive yourself and your groups a face — tap any avatar, add a photo. It shrinks small and lives only in the private vault, never the gallery.

🌙 Works in the backgroundLeave Suchi, open other apps — your call keeps going and your messages still arrive.

🧮 Calculator disguiseThe app looks and works like a calculator until your PIN and = open it.

🚫 Delete for everyoneHold any message you sent — one tap erases it on your phone AND the receiver's. Photos included.

🌫 Vanishes without a traceDeleted messages disappear completely — no "message unsent" note left behind. No questions, no arguments.

🖼 Photos that can't be savedPictures live only inside Suchi's private vault — never in the gallery. Screenshots are blocked app-wide.

⏳ Self-destruct timersMessages erase themselves 5, 10 or 30 seconds after opening.

⏱ Auto-lock, your wayLocks the moment you leave — or after 1, 5 or 10 minutes if you prefer. The 🔒 button always locks instantly.

🧨 Panic wipeOne tap destroys everything on the device — instantly and forensically.

👨‍👩‍👧 Group chatsEncrypted separately to every member — Signal-style.

🛡 Safety numbers & QRVerify a friend's identity in person, get warned if keys ever change.

📸 No-trace cameraShots go straight into the chat — never into your gallery — and location (GPS) data is stripped before sending.

🎤 Hold-to-talk voiceHold the mic — it glows red while recording, let go to send.

😊 Built-in emoji panelOne tap beside the message box — say it with a smile.

🕊 Nameless serverOur own relay keeps everything in memory only — restart it and it forgets everyone. Its diary records events, never names. Even we can't see who uses Suchi.

🕊 Pure. Private. Forever. — in plain words

No phone number. No email. No account. No real name. Pick a nickname, get a Suchi ID — that is all you ever give us.
Messages are scrambled on YOUR phone before they leave it. Our server moves sealed envelopes it cannot open.
The server keeps no names on disk — ever. Names live in memory only; every restart is total amnesia. Its diary writes "a message passed" — never whose.
Even the owners are blind. We built Suchi so that we ourselves cannot read you, count you, or list you.
Undelivered messages self-destruct on the server after 7 days. Delivered ones vanish the moment your phone picks them up.
No ads, no analytics, no trackers, nothing sold. The product is the app — never you.

🕊 Free. Forever.

Suchi is completely free — no card, no trial clock, no subscription, no catch. Privacy is a right, not a product.