Each application, and the Launcher Application itself, can be used in cursor or selector mode (settable via the system control panel).
All apps start out by default in selector mode – the optical track pad on the temple or Wireless Finger Controller generates track pad up/down/left/right events. Apps designed to detect those events for normal operation are easiest to use.
Some off-the-shelf apps that expect touch input do not see trackpad events, so cursor mode can be used to click on the App’s UI. The mode for each app is persisted, so if you find an app is in cursor mode, it was set that way during last use. You can switch it out of that mode, and it will be remembered.