Our application uses the TI bluetooth chip CC2540. We are in development of a key fob produced by Radius Alert Systems.
The application monitors the key fob using an accelerometer that is monitored by a progress bar. The Scan button scans the bluetooth devices in its area, looking for the bluetooth device that is in production by Radius Alert Systems. The battery bar monitors the battery level on the device in production by Radius Alert Systems.
This key fob device is connected to this iPhone 4S only application. When the bluetooth key fob device leaves the 50 foot radius, it notifies the iPhone that the device is out of range.