CortexOS
Leader in The Zero Knowledge AI Journal Category
CortexOS looks like a journal. It doesn't behave like one.
Write an entry and see Deep Analysis, and the AI re-reads it slowly, remembers what you wrote three weeks ago, and writes back like a thoughtful letter from someone who's been paying attention. Users tell us they cried. Or laughed. Or finally understood something about themselves.
Some days you don't want advice. You don't want to be fixed. You just want someone to listen and ask the right questions; that's Reflections. A conversation, typed or spoken, with something that never judges.
And some thoughts shouldn't be kept at all. Vent & Burn lets you say the ugly thing out loud (flames rise while you record) then burn it. Gone, unrecoverable. Or save it, if it turned out to matter.
Underneath everything sits the Psyche Layer: a private picture of you that every conversation reads from and adds to, so the app feels less like a tool and more like a continuation of yesterday's conversation.
All of it runs on your phone. Encrypted so even I can't read it.
Your Mind, Encrypted.
iOS + Android, 7-day free trial: https://cortexos.app
Most journaling apps upload your entries to a server and process them in the cloud. CortexOS does the opposite; a full language model (Llama 3.2) runs on-device, detects 20+ emotions, flags cognitive distortions, and builds a psychological profile over time. While this happens, nothing ever leaves your phone.
The encryption uses AES-256-GCM with Argon2id key derivation. I built it so that even I, as the developer, cannot read your entries. If you lose your recovery phrase, your data is gone forever. That's not a bug - that is the proof it works.
Solo founder, bootstrapped, built from Malta. Started it as a side project late 2025, then I lost my job in January 2026, and had a ruptured brain aneurysm thirteen days later. Finished the app while recovering. Shipped iOS on March 22nd 2026. Android is coming next - very soon.
If you journal or want to start, CortexOS is waiting for you. Read more about the product on our official website; https://cortexos.app
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The shift since your earlier version is interesting.
Back then you talked mostly about analysis and privacy. Now you’re describing listening, reflection, and continuity much more prominently. Curious what you saw from users that pushed the product in that direction.
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