Features
Everything shipped in the SimXmil Android app today — organized the way it's built: an encrypted core, a privacy toolkit, and a field-ready utility layer on top.
End-to-End Encryption, Diffie-Hellman at the Core
Every conversation opens with an ECDH key exchange that only the two of you can complete, then runs under a full Double Ratchet so each message gets its own disposable key. Read one message and you've read exactly one message — nothing before or after it comes free.
Guhya Burn
One tap wipes every message, key, and cached file from RAM and the server — nothing left to recover, nothing for a lost phone or subpoena to dig back out.
Radical Transparency
We don't ask you to take our word for it. A public transparency view lets you see how and where your data actually lives, in plain terms — so the claims we make about your privacy are something you can check, not just something you're told.
Zero-Trace Delivery
The moment a message is delivered and opened on your device, its ciphertext and message fingerprint are wiped from the server — no delivery log, no stored copy, nothing kept that ties to what was said. After that, the message exists on the devices it was sent to and nowhere else.
Voice Calls, No Phone Number Needed
Call and get called with nothing but your Guhya identity — no SIM to link, no number to hand out, and no number sitting in a contact list waiting to leak.
Prabh V1 — Self-Healing Lab
An engine that watches the app the way you'd want a mechanic watching your car — catching crashes as they happen, repairing corrupted local state before it costs you a conversation, and flagging anything that looks like tampering. Most of what breaks gets fixed before you ever notice it broke.
Steganography, Hidden in Plain Sight
Slip an encrypted payload inside an everyday-looking photo using LSB steganography. To anyone scrolling past, it's just a picture — only someone holding the key knows there's anything hidden inside it at all.
No phone number required
Free voice calls and chats without a phone number — no SIM linking required.
End-to-End Encryption
Every message is encrypted on-device using ECDH (Diffie-Hellman) key exchange and AES-256-GCM. The server only ever sees ciphertext.
Double Ratchet
A full Diffie-Hellman + symmetric-key chain ratchet gives every message its own key, so compromising one message never exposes the rest of the conversation.
Group Forward Secrecy
Group chats use wrapped sender keys with their own ratchet, so group messages get the same forward-secrecy guarantees as 1:1 chats.
Voice, Media & File Sharing
Photos, voice notes, documents and files all travel through the same end-to-end encryption pipeline — nothing bypasses it.
Reactions & Threaded Replies
React to any message and reply in-thread, in both direct and group chats.
Disappearing Messages
Set any chat to auto-delete after a chosen interval, from a few seconds up to a week, so a conversation doesn't outlive its purpose.
Edit & Delete for Everyone
Fix a typo or pull a message back on both ends of the conversation, within a short window after sending.
Optional Read Receipts & Typing Indicators
See when a message lands and gets read, and when someone's mid-reply — or switch either signal off, per chat or app-wide.
Tracker-Free Link Previews
Shared links unfurl into a title and image without pinging the destination site or leaking a tracking pixel back to whoever sent the link.
Offline Send Queue
Messages composed with no signal wait in a queue and go out the moment connectivity returns — nothing gets silently dropped.
One Identity, Every Device
The same session state carries across web and Android, so a conversation started on your phone picks up exactly where it left off in the browser.
Encrypted Backup & Restore
Export an encrypted backup protected by a passphrase (PBKDF2, 250,000 rounds) — restore your history on a new device without a plaintext copy ever touching disk.
Backup Recovery on Reinstall
Reinstall or switch phones and unlock your existing identity with your backup passphrase instead of losing history to a silently-generated new key.
Secure Device Transfer
Migrate your identity and keys to a new phone directly, without re-registering or losing history.
Multi-Device Key Backup
Link additional devices to the same identity using passphrase-wrapped key backup.
Encrypted Voice & Video Calls
Calls are set up and carried end-to-end, with a dedicated foreground call service so connections stay stable in the background.
Group Voice & Video Calls
Bring more than two people into an encrypted call, with the same per-call key exchange used in 1:1 calls.
In-Call Encryption Indicator
A visible marker confirms the call's encryption stays intact for its full duration, not just at connect time.
Adaptive Call Quality
Audio and video bitrate adjust automatically to the connection you have, favoring a stable call over a stalled one.
Picture-in-Picture Calling
Keep a call running in a small floating window while you check a chat or another app.
Reliable Call Sessions
Duplicate-call guards, proper stale-call handling, and fast connect states — calls ring, connect, and end the way they should.
Call History
A clean, searchable log of past calls, including missed calls.
Group Creation & Invites
Create groups and invite people via shareable join links.
Group Admin Controls
Promote, remove, and moderate members, with clear on-screen feedback for every admin action.
Granular Group Permissions
Decide who can send media, add members, or edit group info — lock any of it to admins only.
Automatic Re-Key on Membership Change
Every time someone joins or leaves, group keys rotate automatically, so a removed member can't read what comes after.
Group Key Setup
A dedicated screen manages group key generation and rotation as membership changes.
Per-Group Mute & Notification Rules
Silence a noisy group without muting the whole app, or set custom alerts for the ones that matter.
Group Description & Shared Media Gallery
A pinned description keeps everyone aligned on the group's purpose, and a gallery view collects every photo and file shared in one place.
EXIF Stripper
Strip camera, GPS and device metadata from photos before you send them — automatically on every outgoing chat photo, or on demand from the standalone toolkit for photos leaving SimXmil through other apps.
Steganography
Hide AES-GCM encrypted data inside an ordinary PNG image using LSB steganography — the image looks unchanged to anyone who doesn't hold the key.
Stego Extraction Tool
Pull a hidden payload back out of a PNG carrying one, using the same key it was hidden with — the working counterpart to the steganography tool above.
App Lock
Require a PIN, pattern, or biometric check before the app opens at all, on top of your phone's own lock screen.
Auto-Lock on Idle
The app locks itself after a set period of inactivity, so a phone left unattended doesn't stay open.
Screenshot & Screen-Recording Block
Block screenshots and screen recordings inside sensitive chats, closing off one of the most common ways a conversation leaks.
Hidden / Decoy Chats
Fold specific conversations out of the main chat list entirely, reachable only through a separate unlock gesture.
Local Encryption at Rest
Everything stored on the device — messages, media, keys — stays encrypted locally, not just while in transit.
Incognito Keyboard
Blocks personalized-learning and analytics on supported keyboards while you type in SimXmil.
Clipboard Guard
Automatically clears sensitive clipboard content after a short interval.
Device Integrity Checks
Detects rooted or tampered devices and warns you before you rely on them for sensitive conversations.
Power Isolation Lock
Optional setting that refuses to open the app until the device is plugged into power — a deterrent against juice-jacking and casual cable-jack risk while charging in public.
Key Verification
Verify safety numbers with a contact out-of-band to confirm you are talking to the right person, not a man-in-the-middle.
Panic Gesture
A configurable shake or key-combo gesture triggers an immediate lock or wipe without touching a menu.
Confirmed Burn / Wipe
Panic-wipe local data on demand — always behind an explicit confirmation dialog, so it can never happen by accident.
BLE Tracker Scanner
Scans nearby Bluetooth LE traffic to flag AirTag- and JioTag-style trackers that may be following you, with background notifications.
RF & EMF Monitors
Passive radio-frequency and electromagnetic-field detectors for on-the-go environmental awareness.
Acoustic Detector
Analyzes ambient acoustic frequency data for anomaly awareness in the field.
Wi-Fi Scanner
Surveys nearby Wi-Fi networks and signal strength.
Signal Strength Mapping
Logs Wi-Fi and cellular signal strength as you move through an area, so you can spot dead zones before you need connectivity.
Compass & Grid Reference
A precision compass plus grid-reference and magnetic-declination tools for accurate navigation.
Distance & Bearing to Waypoint
Drop a waypoint and get a live distance and bearing reading as you move toward it.
Barometer Altitude
Uses the device barometer to estimate current altitude.
Speed Tracker & Measure Tool
Track movement speed, or measure real-world distance directly from your device.
Offline Location Tool
A location and gazetteer tool that keeps working without a live data connection.
Offline Map Caching
Download map tiles for an area in advance so the location tool keeps working with zero connectivity.
Sun, Moon & Tide Almanac
Sunrise, sunset, moon phase, and tide predictions, useful for planning around daylight and water conditions.
Morse Flashlight Signal
Type a short message and the device flashlight blinks it out in Morse code — a low-tech signal for zero-visibility situations.
Night Vision Shield
A red-shifted low-light screen mode that preserves night vision in the field.
Combined Tactical Dashboard
All of the above, brought together in one glanceable utility screen.
OTP Login & Onboarding
Simple, secure sign-in with one-time-passcode verification and guided onboarding.
Device Management
See every device linked to your account and revoke access to any of them at any time.
New-Device Login Alerts
Get notified the moment your account signs in from a device that hasn't been seen before, with a one-tap revoke.
Session Management
Review every active session with its approximate location and last-active time, and end any of them individually.
My Data
Inspect and export what SimXmil stores about your account, on your terms.
Portable Data Export
Export your account data in a standard, readable format whenever you want a copy outside the app.
Self-Serve Account Deletion
Delete your account and everything tied to it directly from the app, with no support ticket required.
Pinned Chats & Search History Controls
Pin the conversations that matter, and clear your in-app search history whenever you want.
Fast, Cached Chat List
Chat previews load instantly from a local cache, with WhatsApp-style last-message previews, even on a slow connection.
Automatic Error Detection & Patching
Prabh Lab watches the app in the background, catches crashes and broken states as they happen, and applies a safe fix or rollback — usually before you'd even notice something went wrong.
Self-Repair Local Cache
If the local message cache or database gets corrupted — a bad shutdown, a rough update — Prabh Lab rebuilds it in place, without wiping your chat history to do it.
Continuous Security Scans
Regular background checks for tampering, unusual permissions, and rooted or compromised device states, feeding straight into the same integrity warnings as the anti-forensics toolkit.
Diagnostic Health Reports
A plain-language in-app summary of what Prabh Lab found and fixed, so "self-healing" isn't a black box — you can see exactly what happened.
Wireless Data Transfer
Move your chats, media, and account to a new device directly over a local wireless connection — fast, device-to-device, without waiting on a slow re-upload.
Adaptive Performance Tuning
Prabh Lab quietly adjusts caching and sync behavior to your device's actual hardware, so the app stays smooth on older phones instead of assuming everyone's on the latest flagship.
Free Core Tier
End-to-end encrypted chat, calling, and the security/field toolkits are free — core encryption is never gated behind a paywall.
Optional Paid Plans
Higher storage and extended limits are available as optional paid tiers, shown as a clear feature-comparison table in-app so you know exactly what each plan adds.
Secure In-App Checkout
Upgrades happen without leaving the app, and every plan entitlement is verified and enforced on our side — never something a modified client could fake.
No Ads, No Data Resale
Paid tiers fund storage and features, not an advertising business — your data isn't sold or monetized on the free tier either.
Ready to try it?
Free on Android, available as a direct APK, and on the web.