You are also able to leverage enigma when building extensions utilizing the Extension API. By default, when you are building an AngularJS-based extension, as opposed to a paint-based one, enigma.js is shipped within the $scope of the extension:

// Enigma until 3.2.2
$scope.component.model.enigmaModel; 
// Enigma from 3.2.3
$scope.component.model; 

Using enigma.js, you can access the App API and perform similar methods to the Capability API, such as getting an object and its properties:

scope.enigmaModel.app.getObject('HXasde1').then(function (obj) {
 return obj.getProperties()
}

Full documentation of enigma.js can be found on their GitHub account at https://github.com/qlik-oss/enigma.js/blob/master/docs/api.md#api-documentation.