Every decision drains mental energy — but most people have no idea when their brain is actually running on fumes.
ThinkLeft gives you a real-time 0–100 cognitive fatigue score based on 4 signals: decisions made, time of day, fidgeting, and app hopping.
After a few days it calibrates to YOUR baseline — so you see your personal peak hours and afternoon slump, not a generic average.
Free. iPhone only.
