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Have you seen those new cars with big expensive HUD systems? They flash the pertinent information on your windshield to keep you informed while looking at the road.
Add the HUD functionality to any car using just your phone with this app. It reflects an information screen on your windshield, giving you the same capability as those expensive cars.
It also warns you when there are speed cams about so you can slow down.
aSmartHUD for iPhone -- $0.99
Want to save money for the next smartphone upgrade? This app will do its part by turning your phone with a compass into a metal detector.
It uses the magnets in the compass to troll for loose change underground along with anything else made of metal.
Metal Detector for Android -- Free
This app uses the smartphone touchscreen and haptic feedback to deliver a pyrotechnic effect complete with "shock" to an unsuspecting victim touching the phone screen.
That's all it does. Kind of a joy buzzer for modern times.
Spark for Android -- Free