It's a fairly straight forward extension, simply providing access from the application to a Swivel component which interacts with the core Swivel library, and which handles the general bucket assignment for users as swivel is accessed. I've also provided a class for integrating the existing Swivel logger over to the primary Yii Logger, and provided a data structure and model for storing the list of features for the application.
The extension is available on the Yii Framework Extensions list, from the GitHub repository or as a composer package.
It's really designed to be installed via composer:
composer require "dhluther/yii-swivel":"~1"
I've tried to keep it lean, but provide a good bit of information about how to implement it and how the Swivel features work on the Yii-Swivel Wiki on GitHub.
I will be creating a 2.0 version shortly as well.
Enjoy! I hope others find it as useful as I think I am going to, and huge props to the Zumba team that developed it and to Stephen Young and his presentation at SunshinePHP 2016!