Challigo Apps
Simple apps for everyday habits.
Simple mini-apps built to upgrade your daily routine and help you build lasting consistency.
5-Minute Starter
Pick one small task and give it five minutes. A free, private starter timer with pause, resume and a choice to stop or keep going. No sign-in needed.
Sleep Cycle Calculator
Find the exact times to sleep or wake so you rise naturally at the end of a sleep cycle, avoiding sleep inertia and morning grogginess.
Focus Interval Timer
A customizable interval timer tailored for ultradian rhythms and Pomodoro work sessions to maintain peak cognitive stamina.
Circadian Light Planner
Calculate your optimal morning sunlight viewing window, caffeine cutoff, afternoon solar anchor, and evening dim-light melatonin onset (DLMO) schedule.
BMI Calculator
Assess your body mass index using Metric or Imperial units with WHO clinical thresholds, healthy target weight ranges, Ponderal Index, and optional waist-to-height screening.
Reaction Time Test
Test your visual reaction speed across 5 or 10 trials with sub-millisecond precision. Track mean latency, personal bests, and psychomotor vigilance jitter.
Ready to turn routine into long-term habits?
Apps give you clarity, but community and structure build momentum. Explore reviewed habit challenges to stay consistent every day.