It might not be possible to use this application on a mobile phone, because the software doesn't appear to be available on Android, the OS you're phone is equipped with. I have also searched in all the available Android stores, including the official website, and nothing comes up.
As an alternative, install Skype and top up your account, then you can call the country you want.
Note: You can use and install Skype because it's compatible with the phone you have.
