DoitBetter Calendar has two types of Add-Ons on the Atlassian Marketplace:
CloudHosted Add-Ons for Atlassian Cloud products that are delivered via the Atlassian Connect framework. These are our Cloud Add-Ons.
ServerDownloadable products or Server Add-Ons that are installed in a server instance of the applicable Atlassian product hosted and managed by the client. These are our Server Add-Ons.