The mobile version of IP Scanner supports URL schemes to launch other apps directly from IP Scanner.  From the device detail view, select 'Open In' to access this feature.   VNC is preprogrammed, but only if your VNC client supports the standard vnc:// sheme.  RDP is generally handled differently by each RDP client vendor.  To configure either RDP or a custom URL scheme for VNC, you'll need to select 'Open in Custom' and follow the instructions provided to enter the url scheme appropriate for your native client.