The Elite HRV app is free for iOS and Android! You can get the app here for iOS or Android.
The Elite HRV app can be found on both Google Play and the Apple App Store. If your phone or tablet supports Bluetooth 4.0, and has either Android 4.3+ or iOS 7+, then it is likely compatible with Elite HRV.
Unfortunately, iPhones and iPads don’t have the physical hardware inside to receive ANT+ signals. The only option to use with Apple devices are the Bluetooth 4.0 heart rate monitors.