Combining the power of your smartphone with the accuracy of the Bike combo kit gives you the features and benefits of other top digital cycle computers for a fraction of the cost. It automatically detects, measures and transmits your bicycle speed and pedaling cadence to your phone in real-time using Bluetooth. This product works with the free iMaze app available on iTunes or Google Play. Have an alternate app you prefer to use? No problem! The sensor is compatible with dozens of other apps for virtually any form of cycling - outdoor, indoor, spin training and more- whatever your cycling activity, iMaze has you covered. Using a speed and cadence sensor is far more accurate than using your phone alone with GPS. Using the iMaze bike sensor set up specifically to your actual tire dimensions will give you the most accurate data possible and turn your smartphone into a powerful cycling computer. Connect to the cloud, upload, and share With the iMaze app you get free connection to the iMaze community cloud to upload and store data for all your rides. Analyze your performance and history from your phone or online from any computer and tablet. Set goals, share your rides with friends and see your progress at a glance. Using low energy Bluetooth Smart 4.0 you can easily connect to your phone. This low energy protocol means that the iMaze speed and cadence sensor can last for 12+ months on the CR2032 coin cell battery. Future battery changes are easy and inexpensive. Simple installation on any bike Installs on any bike in minutes with simple hand tools. Includes step by step instructions for measuring wheel circumference for speed and mileage accuracy. It"s easy and just takes a few moments. Your device must be Bluetooth® 4.0 compatible. The Bike Combo Kit works with iPhone 4S/5/5S/5C, the latest generation of iPad & iPod and Bluetooth® Smart Ready AndroidTM devices running Android 4.3 or higher versions.