Answer by user3078359 for How can I access my localhost from my Android device?

I used this process:

• Install Fiddler on the PC
• Set up PC and Android device following these excellent instructions
• Simply go to the browser on the Android device and type in http://ipv4.fiddler to access the localhost

Note that this process requires you to change the WiFi settings on the Android device at the start and end of every session. I found this less painful then rooting my Android device.