The Apps and Add-ins themselves are currently not offline capable. But in the case of the Content Chooser and Template Chooser, you can use functionality offered by the storage provider (like SharePoint or OneDrive) to replicate a copy of templates and content to your local device and make them offline accessible.Office Add-insWe are actively discussing offline capabilities with multiple engineering teams at Microsoft to find ways of supporting offline functionality, like serving templates and contents to users directly in our Add-ins, even when there is no network connection available.Vote for Add-in offline capabilitiesIf you want to support us in your efforts with Microsoft then we would kindly ask you to up-vote this Uservoice article.Check out the list of all UserVoice entries we are backing. Learn more.