You need to accept Google Voice’s terms of service in order to make free calls via Talkatone. To do this:
Note, that since Talkatone currently leverages Google voice, we are constrained by the functionality Google Voice offers in countries other than the US. Thus:
However, you can always make and receive free calls to other Talkatone users, so invite your friends to Talkatone!
Additionally you can always send free messages from your mobile phone to Facebook and Google friends via Facebook or Gchat.