This is what was posted on Zdnet on Oct 16...
Following AT&T, Sprint and T-Mobile, Verizon is finally starting to offer Wi-Fi Calling features to its subscribers with iPhones. Unlike the other big three carriers, however, the feature isn't a native phone experience. Instead, Verizon has added calls over Wi-Fi to its own messaging app.
PhoneScoop noticed the app update ion Friday in the iTunes App Store for Verizon Message+. The updated software for iPhones and iPads now lets you place domestic or international calls over a Wi-Fi network at no charge.
The key difference here is that other carriers have made Wi-Fi calling a more seamless experience because there's no change in user behavior: Once Wi-Fi calling is enabled, customers simply use their standard Phone app and the call is placed over a local network.
And in the case of Google's Project Fi, which also supports calls over Wi-Fi, the calls seamlessly transfer over to the cellular network of T-Mobile or Sprint when leaving range of a home or public wireless network. Verizon's solution won't do that while other carriers do offer call handoff capabilities.
Verizon's implementation by comparison is far more limited because it requires a separate app. There's no call transfers to the carrier's cellular network either: Walk beyond the range of your Wi-Fi network using Message+ and the call will be dropped.
The new feature is limited even further by only working on iOS -- sorry, Android fans -- and only for the iPhone 6, 6s, 6 Plus and 6s Plus.
In fairness though, AT&T's own recent launch of Wi-Fi calling is limited to the same phones and mobile platforms. The big difference though is that AT&T's service works directly in the native iOS Phone app once Wi-Fi Calling is enabled in settings.