Question: I switched my project from pg2.9 to 3.0 and got one issue which drives me crazy, and I am not able to fix it now:( So, basically everything is working fine, but not backbutton event listener. 

```js
      bindEvents: function() {
        document.addEventListener('deviceready', this.onDeviceReady, false);
      },
      onDeviceReady: function() {
        document.addEventListener('backbutton', this.onBackButton, false);
      onBackButton: function() {
        alert('backbutton');
      }

```

deviceready event is firing very well, but not backbutton. 
Also, I found interesting message from logcat:

> 
> exec() call to unknown plugin: App
> 
> 
> 

Any ideas?

Answer: 
Ok, fixed this. For some reason phonegap is not adding their plugin called App which have all that functions. just add to config.xml next lines:

```
    <feature name="App">
        <param name="android-package" value="org.apache.cordova.App" />
    </feature>

```
I faced this bug after upgrading to cordova 3.1. Turns out that this has to be explicitly added in config.xml phonegap 3.\* onwards.

```
<feature name="App">
        <param name="android-package" value="org.apache.cordova.App" />
    </feature>

```

See this [link](http://www.icenium.com/resources/forums/icenium-general-discussion/any-known-issues-with-backbutton-event-with-cordova-3-0-project#8Usgc41hT0--o7srDw6OQg)