Oh, feature phones… Yeah, that must be it. I was thinking about smartphone apps. Skype has been around for years even before smartphones became popular. Last sm

Oh, feature phones… Yeah, that must be it. I was thinking about smartphone apps. Skype has been around for years even before smartphones became popular. Last smartphone I had was way before Android was born, so I can't exactly name rivals of WhatsApp, but I'm sure I heard about many of them even before I heard about WhatsApp. There're many messengers (even completely free ones), there're bridges between them, there's Viber. But, yes, availability on feature phones explains a lot.