The most common free unofficial implementations for Android are Gadgetbridge (that also supports Pebble devices and is focused on notifications more than on fitness purposes), Tools & Mi Band and OpenBand (focused solely on fitness and doesn't support notifications as of October 2015).
安卓最常见的免费非官方应用程序是Gadgetbridge(它也支持Pebble设备，并且更关注于通知而不是健康目的)，工具和Mi Band和OpenBand(仅仅关注健身，并且截至2015年10月不支持通知)。