With Chargebee you can provide addons for trial to your customers, so your customers know the feature before signing up for it.
Say, with your service you provide Google Calendar as an addon. For the customers who are interested in signing up, they can use the Google Calendar feature for a limited number of days as a trial before using it along with the subscription.
Trial period for addons is available only via API. You can save the details of the addon's trial period in the metadata of the addon.
To enable this feature for your site, contact firstname.lastname@example.org.