You can make free calls from mobile to mobile any where in the world. It is necessary that both mobiles should be connected to the internet and download skype in both of them.
Actually you will call from Skype to Skype via internet, but it seems like to from mobile to mobile calling. It is free calling method from one mobile phone to another and anywhere in the world.
You can send Skype link diectly from here to your mobile phone.
Send Skype to Mobile Phone for Free Local and International Calls: Click Here