I like
voip.ms for all the features, but the cost can add up for heavy users.
I have also done some testing of SimonTel/GV.
Another service that I have tried with my old virtual office Google voice phone number is:
GVsip >
https://www.gvsip.com/The web site states:
Enhance Google Voice
GVsip is a free cloud based service that connects you to
Google Voice and turbo charges its capabilities.
There is a "free" plan that allows 1,000 minutes per month.
There are also several paid options that I have not tried.