The app receives browser and OS information from Intercom as a combined User agent field. Simply search for the user agent field in Intercom for Jira when you configure visible fields to show browser and OS details in the conversation panel.
How much does Intercom for Jira cost?
Please have a look at the pricing tab on the Intercom for Jira Marketplace listing to get a rough idea.
Intercom for Jira is priced based on the number of active users in your Jira instance (Atlassian pricing model). It does not matter how many users/leads or teammates you have in Intercom or how many conversation links you create.