How to use Bluetooth hid

I don't think this is true now. HID just needs to be enabled when you pair it with your device

Well I'm new to this, but when exactly is boot0.js executed, when I pair with another device or a single time on start?

The code in boot0.js is basically:

var s = require('Storage').readJSON('setting.jso­n',1)||{};
if (s.HID) { // Human interface device
    Bangle.HID = "(...)";
    NRF.setServices({}, {uart:true, hid:Bangle.HID});
}

so when HID is not enabled in settings while starting and boot0.js is only executed on start the NRF.setServices() never happens, correct?