There are NO apps to officially install. Do a forum search, magnifying glass icon upper right, as this is a well discussed limitation of the second generation single bay My Cloud units. Only the My Cloud Mirror and above units support third party apps.
Unofficially there is a way, using SSH to modify the v2.x single bay My Cloud firmware, to enable adding certain third party apps. This is NOT supported by WD. See the following discussion:
http://wdstagingsplit.staged-by-discourse.com/t/wd-mycloud-gen2-enable-apps-install-tab-apps/177885/
