So I decided to see if I could control my trains using the new Android app running on a PC.... It worked!
Here's how....
1) Get software to let your PC act like an Android device. If you google for "Bluestacks", you will find a free software package that lets you run apps on your PC. Download and install it.
2) Run Bluestacks. Once up and running, search for MTH DCS on Google Play, just like you would do on an Android device. Install MTH DCS Wifi App.
3) If you have a PC that has built in wifi, like a laptop, turn the wifi on and connect to your WIU. My PC also has wifi built in so it worked fine. If you also have a wired wifi board in the PC, turn it off (disable it)
4) In Bluestacks, run the MTH DCS app..... that's it. It works beautifully!
Sorry, I don't have a Mac, so I don't know if there is an Android emulator that would work the same way.
Ed
ps. I also noted that with a steam loco, pressing on the whistle handle works, but pulling the handle down works better!