Last night Horizon Workspace 1.8 was released. While being a minor release it comes with some major new features and functionality.
Citrix-based Application (XenApp) integration
From the Horizon Workspace User Portal, users can now launch Citrix-based applications via XenApp 5.0, 6.0, and 6.5 using single sign-on. This feature requires Citrix Receiver to be installed on the client and supports Mac, PC, iOS and Android devices.