Tap Settings across the bottom of the screen.
Tap Default View.
Tap Servers.
Tap Settings in the upper left corner to go back.
Tap Servers across the bottom of the screen.
This way every time you open the Horizon App it will default to the Servers screen instead of the Recent screen. Using the Servers screen you will only ever see the desktop(s) you have entitlement to instead of seeing the history of each desktop you have ever connected to.