CortexLab - Track your brain performance in 5 minutes a day

Hey everyone! I'm Yun, the maker of CortexLab. I built this because I wanted a simple way to know if my brain was actually performing well on any given day — not just a vague feeling, but real data. As a developer, some days I feel sharp and productive, other days I can't focus at all. But I had no way to quantify that. So I built CortexLab — a 5-minute daily checkup that measures 5 cognitive abilities: alertness, processing speed, memory, multitasking, and insight. The idea is simple: take the test daily, track your trends, and start noticing what actually affects your brain performance — sleep, exercise, caffeine, stress, whatever it may be. Built with Next.js, React, Supabase, and TypeScript. Available in English and Japanese. I'd love your feedback — what would you want to see next? Thanks for checking it out!