I thought the Synscan app was supposed to be used in conjunction with the Synscan wifi adapter, essentially to replace the need for using the handset and/or cables? I've been using it with the Wifi adapter with differing levels of success. It seems to work OK on a PC, although I like to use it with Stellarium so I can see a computer rendition of the sky at the same time, so the Synscan App is generally running in the background just for the initial alignment and any fine tweaking of the goto. I've also used it on an iPhone, but with apple products you can't run the Synscan app and any other sky program (Stellarium, Sky Safari, etc) on the same device, so I need to run Synscan on the Iphone and SkySafari on an iPad. The wifi adapter seems to work pretty well, although the synscan app itself tends to be a bit buggy in terms of alignment/tracking.
there is instructions in the download of the app to connect via hand controller with a serial cable i have not done it as i have the wifi adaptor3. Connect to Mount
1) Click "Settings\Connect Settings"
2) Choose "UDP" for working with a SynScan Wi-Fi adapter.
Let PC connect to the same network as the SynScan Wi-Fi adapter.
3) Choose "Serial" for working with a serial port adapter connected to the "Hand Controller" port on the mount.
Enter the correct "Serial Port" number.
4) Go back to home page and click "Connect" to establish connection between application and mount.