Pure Offline Cycle Note vs Crabwise

This gentle offline cycle tracker stores all your period, ovulation & PMS data only on your phone, no cloud uploads. Log symptoms & moods easily, get warm local reminders. Suitable for regular/irregular cycles & mild fertility planning. Soft lavender cute design keeps your intimate body rhythms fully private.

Crabwise is an offline E6B flight computer built for student and private pilots: the six calculations you learn on paper, with type large enough to read at a glance. WIND & GROUND SPEED Solve the wind triangle both directions: find your heading and ground speed, or work backward from heading, track, and ground speed to find the wind. PRESSURE & DENSITY ALTITUDE See the classroom rule of thumb and the exact ICAO Doc 7488 answer side by side, so you know how much margin you actually have. TRUE AIRSPEED & MACH The quick 2%-per-1000-ft approximation and the exact compressible calculation, together. FUEL / TIME / DISTANCE Solve for any one of the three from the other two. CROSSWIND Headwind and crosswind components for any runway and wind. CONVERSIONS Seven unit families: distance, speed, altitude, temperature, pressure, weight, volume. CRABWISE PRO, ONE-TIME PURCHASE ($9.99) - Aircraft profiles: save cruise speed, fuel burn, usable fuel, empty weight and arm, and limits for every aircraft you fly. - Leg planner: chain legs from true course to compass heading, with running totals for time and fuel. - Weight & balance: plot your loading against your aircraft's envelope, checked live as you type. - History & export: save any result and export it as text or CSV. Free forever: all six calculators, every unit, every language, extra-large type. No ads, ever. No trial timer, no subscription. For training and planning cross-checks. Always verify against your aircraft flight manual and official sources. Not for primary navigation. No account. No ads. No tracking. Works offline. Available in English, Spanish, and Polish.