I was referring to Crochik's MyContacts app. It doesn't show up in IM Accounts list. In MyContacts' Call/SMS routing preferences, I have set my first preference to Google Voice. I think GV only shows up in this menu if TOR is installed. There is another Google Voice (MyContacts) option too. So if I try calling any contact from the widget and if I am not already signed in, it signs into GV and then places a call using GV account.