I'm not a developer, just a designer.
You can also contribute to improve this wonderful plugin to add a lot of interesting functionality.
Buy a (Kirby) license
You can purchase your Kirby license at http://getkirby.com/buy
A Kirby license is valid for a single domain. You can find Kirby's license agreement here: http://getkirby.com/license
Cartkit comes with a small demo website and a fully configured panel. Feel free to modify it and play with it as much as you like.
You can find the login for Kirby's admin interface at http://yourdomain.com/panel. You will be guided through the signup process for your first user, when you visit the panel for the first time.
Kirby does not require a database, which makes it very easy to install. Just copy Kirby's files to your server and visit the URL for your website in the browser.
Please check if the invisible .htaccess file has been copied to your server correctly
Kirby runs on PHP 5.3+, Apache or Nginx.
If you are familiar with Git, you can clone Kirby's Cartkit repository from Github.
git clone --recursive https://github.com/starckio/cartkit.git
Issues and feedback
If you have a Github account, please report issues directly on Github:
Otherwise you can use Kirby's forum: http://getkirby.com/forum