Whatever you pick in Settings: knots, mph or km/h for speed; feet or meters for altitude; inHg or hPa for pressure; °C or °F for temperature; gallons, liters, lb or kg for fuel and weight. Every calculator follows your Settings choice.
Crabwise shows the classroom rule of thumb (the quick mental-math version most pilots learn first) and the exact ICAO Doc 7488 calculation side by side, so you can see how close the shortcut actually is for your numbers.
Crabwise is a training and planning cross-check, not a certified navigation instrument. It has no GPS, no location access, and no live weather. Always verify its numbers against your aircraft flight manual and official sources before you fly, and never use it as your primary means of navigation.
Open Settings and tap Restore Purchases. If you bought Crabwise Pro on this same App Store or Google Play account, it unlocks again immediately — no account or login needed.
Email the details below, including your device and the exact inputs you used. A wrong calculation is treated as a priority fix.
Contact: sales@syntheticm2m.com