Could you please clarify if there is no remote desktop cursor displayed when you connect to a remote Host via the Android Viewer app? If there is a remote desktop cursor visible, then you should be able to control it by using these gestures:
Mark, be aware that if you are connecting to a host computer that has no physical mouse connected, the mobile apps do not locally render a virtual cursor. A workaround is to enable "Mouse Keys" on the host computer as described in this post: