I designed an AI second brain companion that connects what no single app can see — looking for builders

Every personal tool you use is a silo. MyFitnessPal knows what you eat. Fitbit knows your steps. YNAB knows your spending. Your journal app knows how you feel. Apple Health aggregates some health data. None of them talk to each other. I kept running into this: I'd notice a pattern in my life — spending more on stressful weeks, sleeping worse after certain kinds of conversations, feeling sharper on days I ate clean — but no tool could confirm it. The data existed across five different apps. The connection existed only in my head. And my head is exactly the thing that can't be trusted to see its own patterns clearly. So I designed Cortex. What it is Cortex is an AI companion that absorbs any signal from your life — health data, finances, mood, diet, social interactions, calendar, habits, whatever you feed it — and finds the cross-domain patterns you can't see from inside your own experience. Not a health tracker. Not a habit app. Not a finance tool. A companion that sees all of it and te