Jetlag Coach builds a personalized circadian schedule around your body clock and flight itinerary. Instead of generic "sleep earlier" advice, it tells you exactly when to seek or avoid bright light, when to sleep, when to time caffeine, and optionally when to take melatonin - all timed to your circadian phase, not just destination time. Adaptation starts before you fly with a pre-trip schedule, and each day's plan realigns as your body clock shifts. Built on decades of circadian research used in aviation, the military, and elite sport. Available on iOS and Android, in English and French. First trip free.