Orlin Martinov

CortexOS - Private AI Journal

Mental-health

I built CortexOS because every journal app I tried had the same problem. They store your most private thoughts on someone else's server, process them through cloud AI, and call it "private" because they wrote it in a terms of service nobody reads. I journal for my mental health. I write about anxiety, relationships, work stress, things I would never say out loud. And I kept asking myself: why am I handing this to a company that could get breached, subpoenaed, or just quietly sell my patterns to advertisers? So I built something different. CortexOS runs a full language model directly on your phone. No cloud APIs. No data leaving your device. Your entries are encrypted with AES-256-GCM, and the keys are derived from a recovery phrase only you know. We literally cannot read your journal. Not because we promise not to, but because the math makes it impossible. The AI detects over 20 emotions in every entry, tracks mood patterns across weeks and months, spots cognitive distortions like catastrophizing and black-and-white thinking, and gives you CBT-informed observations. It is like having a thought partner that remembers everything you have written but has zero ability to share it with anyone. It also does things no journal app does. It groups your entries into 7-day chapters with AI-generated names. It builds a psychological profile that evolves with every entry. It generates a therapist-ready PDF report of your emotional patterns without including a single word from your actual journal. And it runs voice transcription on-device too, supporting 99 languages, with zero cloud processing. I did not build CortexOS to compete with Notion or Day One. I built it because I needed a journal that could actually help me understand myself without making me trade my privacy for the privilege. https://cortexos.app Your Mind, Encrypted.