If like me you live in a remote village then mobile phone coverage is limited. The last few versions of the iPhone have supported WiFi calling but its a feature that few carriers seem to want to implement for their customers.
Orange or as its now known EE turned it on earlier this year but only for customers who bought there phones from them.
I switched to Vodafone last year as its the only network I could get any cover in my village but even then its touch and go. Well they have now announced wifi calling starting this month so I wait for a carrier update but I am not too hopefull as there website says its going to be for the iPhone 6s and 6s Plus only. Lets hope that’s not true.