Just had an idea and decided to give it a try. And whaddya know? It worked! I'm able to use the GoPro App on my Windows 8 laptop! Wanna know how?
1. Download BlueStacks:
Run Mobile Apps on Windows PC or Mac with BlueStacks | Android App Player
2. Download the Android version of the GoPro App:
3. Double click the APK (should now be associated with BlueStacks), and it will install automatically
4. Turn on your GoPro's Wifi
5. Switch your laptop's Wifi to connect to the GoPro
6. Start BlueStacks and launch the GoPro App!
With mine, I can't see the preview yet. It does say "Starting Preview", but nothing happens. I can still mess with all the settings, start and stop recording, and turn the GoPro on and off as easily as on a phone/tablet, though. Future updates will probably improve compatibility to the point that will eventually work, hopefully.