When first opened, ShowTouch for iOS will display a list of available controllers (V16Pro, V4Pro, VCore) on the network. If your controller isn't being displayed, you should verify a few things:
- Is the iOS device connected to the same network as the controller? Is there a strong wifi signal?
- Is the controller visible to other devices on the network? To verify, use WinScript Live to try and discover the controller.
- Is the iOS device using a static IP address? Because Touch uses a special "broadcast" packet for device discovery, iOS requires a default router and DNS address to be defined when a static IP is set, even if they aren' t being used.
Here's some additional information from Apple on troubleshooting iOS network issues: http://support.apple.com/kb/TS1398