Everyone these days has a cellphone, but not everyone has a smart phone - those things like iPhones or Androids which are nothing less than miniature computers.
I actually have a Samsung Galaxy Note 8 with Skype installed, which I can use, but I've been contemplating getting an actual iPhone.
To that end, I've been scoping out the messages in a forum called Clear Talk, which is dedicated to cell phone usage around the world It's pretty interesting, actually, to see the hoops people have to jump through in certain countries to use their cell phones, let alone their smart phones!
Check out their message boards if you're interested in this type of thing:
The forums are part of a website called Clear Talking as well. They've got everything there about actually buying cell phones to job opportunities in the field.