1. Full version of the speedometer gives you ability to work in background, GPS tracking, waypoints, trip cost computer, Siri shortcuts for applying speed limits and controlling track recording, 100+ customization options and more.

2. GPS Black box gives you point by point time, speed, location and altitude data for the last 20 minutes of your travel.

3. Under the open sky, within 5-10 seconds GPS indicator will become green and speedometer will start showing the speed.

4. * A bit of instructions: If speedometer doesn't show you the speed, just be sure to be under the open sky to have GPS signal.

5. Don't throw the app or iPhone away just because of that! :) Let us use the article's last sentence here: "Those who use GPS altitude to aid in landing their small plane should have their insurance policies paid up at all times".

6. Our speedometer shows your current location and you can share it easily (sms/text, email) with car assistance services, ambulance or friends.

7. ** If you wonder why gps speedometer may show 3-5 mph (3-8 kmh) less than a car's speedometer, you can take a look here: (tomtom's discussion thread).

8. Does your car become sluggish on those steep climbs? Is it possible you got too high in mountains ? Our built-in altimeter will provide you with accurate readings that indicate your height over sea-level.

9. A high quality Speedometer app with the same sophisticated brain inside as our paid version.

10. *** And here is an amazing article explaining why GPS might show you 80ft (or -80!) altitude when you are laying on the beach.

11. Speedometer for iPhone and 3G-iPads.

12. Liked Speedometer 55 GPS Speed & HUD? here are 5 Navigation apps like Sailboat GPS Track Data Logger; GPS to SMS 2 - Try it!; Trucker Path: Truck GPS & Maps; GPS - Way Home Finder App; My GPS Tape Measure;