Beets BLU Heart Rate Monitor is compatible with:

iOS

Android

Note: Most Android-based smart phones already have hardware that supports Bluetooth 4.0 (for example: HTC One, Desire; Sony Xperia V, Sony Xperia Z; Google Nexus 4; Explay Advance; Alcatel One Touch ; ZTE Grand S), but the Android system itself does not yet support it. As soon as the support becomes available, the range of supported devices will expand significantly thanks to Android-based devices