According to Google.com, users no longer need invitations to use Google Voice, as Google no longer restricts users to the previous rule of three invitations per user. Google is now allowing anybody located in the United States to sign up and use Google Voice, as of 2015.
Google Voice is a service that allows a user to obtain a phone number that can be used through the user's Gmail account, on the Google Voice website or through an app available from the Google Play Store. Google Voice also allows users to port a phone number over from mobile phone carriers.
Google Voice offers users a "do not disturb" feature that forwards all calls straight to voicemail for a predetermined period of time. Google Voice also allows users to switch over to the Google Voicemail service for existing phone numbers.
SMS features offered by Google Voice include receiving and replying to SMS messages by email, and sending an SMS to multiple recipients simultaneously. Users can also install an extension in Chrome that allows notifications to be delivered straight to the browser.
Another unique feature of Google Voice is that it allows a user to change his Google number if he is unhappy with it. Google Voice also has keyboard shortcuts available for users to utilize in order to make calls or send messages with short keystrokes.