In another thread, SteveInWA correctly cautioned that the Google Voice settings web pages are NOT mobile friendly. The usual step of clicking the "Request desktop site" menu option is ignored and the mobile page is lacking the critical
Add Another Phone link.
But, I have stumbled upon a way to access the desktop page from my mobile.
a. In your mobile browser, open the
Call forwarding with your Google number page,
https://support.google.com/voice/answer/165221?hl=en.
b. Click the
1. Go to Google Voice link on that page.
c. Click the "Request desktop site" option in your browser's menu.
d. After the page reloads with the desktop version, click the Gear Icon in the upper-right and select "Settings".
Presto! You should find yourself in the familiar GV Settings desktop page with the necessary tools to add a new forwarding phone number.
For the record, this worked using Chrome for Android, version 51, under Android 5.1 on 22.June.2016. I hope it works for you.
Stan
