You can buy some other Android phones SIM free now and wifi calling will work
Quote:
“ Samsung Galaxy S7, S7 edge, Nexus 5X, Nexus 6P, Lumia 550, 650, 950, 950XL and HTC 10.”
EE do keep the wifi calling page up to date:
http://ee.co.uk/help/phones-and-device/wifi-calling
It doesn't seem that stable on the 5X though, but it's fine on the 6P
EE also have a habit of saying phones support it then saying it's not available yet.
E.g. The Sony Xperia XA had a
press release about it, but they haven't enabled it and no idea when it will work.