如果不在乎"Land Line"的話,Google Handout Dialer 可以用來Google Voice撥出
Now call any phone number in the world from your Hangouts app without using your cell plan minutes. Most calls to US and Canada are free!
接受別人打到你Google Voice可以用Google Hangout
Google Hangout + Google Hangout Dialer 完成了Wifi/Cell Data Call.
我隻在自己 Nexus 5X 手機上試過,估計Wifi only的各種pad應該也可以