Calculator

A serverless, peer-to-peer messenger for Android. No accounts, no phone number, no servers. Messages are end-to-end encrypted with post-quantum cryptography and delivered directly between phones over the Tor network. The app is disguised as a working calculator.

NiiX is experimental software and has not had an independent security audit. Do not rely on it in situations where your safety depends on it.

How it works No servers. There is no NiiX server anywhere. Your phone runs its own Tor onion service, and your contacts connect to it directly. No company operates infrastructure that could log who talks to whom, store your messages, or be compelled to hand them over — because it does not exist. Post-quantum end-to-end encryption. Messages use Signal's libsignal (PQXDH: X25519 + Kyber), so they stay protected even against a future quantum computer that recorded today's traffic. Everything over Tor. All traffic is routed through Tor. Neither you nor your contact learns the other's IP address, and the connection is hidden from your network provider. Encrypted at rest. Your messages and keys live in a SQLCipher database. By default the encryption key is derived from your passcode; without it, the data on disk is unreadable. If you turn passcode protection off (Settings > Security), the database is still encrypted, but by a key tied to your phone's hardware alone — as strong as your phone's own screen lock, not by anything only you know. Calculator disguise (on by default). The app looks and behaves like a real calculator. Your actual messenger opens only when you type your passcode and press =. This can be turned off in Settings if you'd rather NiiX show its real icon and name; doing so requires a passcode to still be enabled, since a disguise with nothing behind it can't hide anything. Duress passcode. An optional second passcode that wipes everything and opens into a fresh account seeded with plausible, harmless conversations, so a coerced unlock looks like it worked normally rather than obviously failing. Only available while passcode protection is on — Settings also has a manual "Wipe all data now" button for when it's off.