Meet the Bad Elf 2300 GPS Pro+: an innovative device that adds GLONASS reception, a barometric altimeter, advanced USB features to your phone. It lets you use your iPad, iPhone, and iPod to get GPS data even when you don’t have an Internet connection. It shows you barometric altitude for pilots and barometer readings for boaters. You can stream data directory to your Mac or PC via its advanced USB connectivity.
The device has a battery that lasts 24 hours. You also get a Bluetooth GPS+GLONASS Receiver that is accurate to 2.5m. There is no monthly subscription is required. Sets you back under $250.