Originally Posted by
Need
In order to use Whatsapp, both parties have to install Whatsapp on their phones. So it is not exactly the same as Facetime as Facetime is pre-installed on all iPhones. Neither Facetime or Whatsapp could call landline. I don't think there is any app that could call landline in another country for free. Google Hangout Dialer could call any number in the world for a fee that is very competitive but not free. Skype has a paid plan for calling too, rates are not bad.. and I think they have unlimited plan to some countries. Also if you are a subscriber to Microsoft Office 360, I think they give you a pool of Skype minutes every month.
I have a Vonage (VOIP) landline in a vacation rental I own. Vonage allows me to designate 2 mobile numbers on which I can then use their app (Extensions) which allows me to call any number for free in 60 countries. The caller does not need to be a Vonage customer. It is, of course, dependant on the plan you have but I need to have a landline there anyway so this is just a bonus.