Bluetooth shutter remote for an android smartphone?

Thanks @Gordon!
I just tried with

var controls = require("ble_hid_controls");
NRF.setServices(undefined, { hid : controls.report });
function btnPressed() {
  controls.playpause();
}
setWatch(btnPressed, BTN, {edge:"rising",repeat:true,debounce:50})­;

and it works like charm!