> There are federal regulations that prohibit operating a GPS at faster than xx mph speeds, basically to prohibit guided missiles, and this would kick in first

> There are federal regulations that prohibit operating a GPS at faster than xx mph speeds, basically to prohibit guided missiles, and this would kick in first (may even trigger an error state in the accelerometer or OS, I'm pretty sure). This app doesn't use GPS, it uses accelerometer. It is 100% legal in the US to operate a GPS while over CoCom/MTCR limits: above 1,000 knots (510 m/s) and/or at an altitude higher than 18,000 m (59,000 ft). The regulation is on the GPS manufacturer, who is required to output null/error/no GPS data if it detects it is above these limits (edit: unless they are licensed, which you can apply for if you're a defense contractor or in aerospace). It isn't like if a GPS device is traveling too high or fast, it is automatically a crime and bricks itself or alerts the authorities.