Not able to retieve device model using ngCordova

I have created a blank ionic project. Using ngCordova, I am trying to retrieve device model.

In my app.js, I added a controller after ionic platform is ready:

.controller('TodoCtrl',function($scope, $cordovaDevice){
    console.log('Retrieving device');
    try {
        $scope.model = $cordovaDevice.getModel();
    } catch (err) {
        console.log('error ' + err.message);
    }
})

In my index.html, I added a placeholder inside ion-content:

<ion-content ng-controller="TodoCtrl">
      <p>{{model}}</p>
</ion-content>

Running on Android device and FirefoxOS simulator, the err.message is:

"error device is not defined" 

You added plugin ?

cordova plugin add org.apache.cordova.device

Yah added.

cordova plugin add org.apache.cordova.device
Fetching plugin "org.apache.cordova.device" via plugin registry
Plugin "org.apache.cordova.device" already installed on firefoxos.

This info help, but only work on FirefoxOS, not Android:

http://www.raymondcamden.com/2014/8/16/Ionic-and-Cordovas-DeviceReady–My-Solution

I think the problem is I am retrieving device info before it is initialized by cordova.js:

"initializing device" controllers.js:5
"adding proxy for Device" cordova.js:846

Is this a bug?