To download the Swimmo application, you need to have an iPhone or a modern Android phone that supports Bluetooth Low Energy.
Most of the Android phones currently on the market do support Bluetooth Low Energy, but please check your phone specs.
How to get the mobile app?
If you have trouble accessing Android link (e.g. China region), here you can download APK file directly. In that case, you need to follow this link for regular updates as well.