How do I get the most accurate result?

• Aim at the plane itself. Put the plane or the tip of its contrail in the middle of the screen. Zoom in if it is a small dot.
• Hold still for a second. JetDex locks faster when the phone is steady and the plane stays in view.
• Keep away from metal and magnets. Cars, railings, steel balconies, magnetic phone cases and wallet cards bend the compass. Take the phone out of a magnetic case if results are off.
• Calibrate the compass. On iPhone, make sure Settings › Privacy & Security › Location Services › System Services › Compass Calibration is on. On Android, if the compass is off, move the phone in a figure of eight a few times.
• Let it learn. Every time you catch a plane when it is the only one around, JetDex learns how far your compass is off and corrects every later catch.
• Give it a clear view. GPS is more accurate outdoors, away from tall buildings.

If two planes are very close in the sky, JetDex may show both and ask you to pick.