With XenApp and Xendesktop, if you wanted to use Skype for Business then you had to first download and install Citrix Receiver and then repeat the process for the HDX RealTime Media Engine. Not anymore. Not a huge deal but important to know.
The new “v2 architecture” of the HDX RealTime Optimization Pack delivers a truly native UI experience while maintaining server scalability. Now Citrix has made it easier to adopt the new solution by creating a new Receiver for Windows package that includes the HDX RealTime Media Engine (RTME).
The new bundle brings together Citrix Receiver 4.4 and RealTime Media Engine 2.0 (a Receiver plug-in) in a single package that’s ideal for BYOD users and at-home workers. Admins can direct users either to the Citrix download page for the HDX RealTime Media Engine or to a page on their own network where they have posted the new bundle. Copying the package to your own network is a recommended practice as it gives you more control over future upgrades. Just be aware that the HDX RealTime Connector on your XenApp/XenDesktop servers must be at least version 184.108.40.2067 (GA release) for compatibility with the new RTME; that is, RTME 2.0 cannot be used with the 1.8 Connector (previous generation architecture); you must uninstall the old 1.8 Connector and install the new 2.0 version.
More at the source: https://www.citrix.com/blogs/2016/02/04/a-receiver-for-skype-for-business/