I built an AI journal that runs entirely on your phone
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
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.