Verizon has had a tumultuous relationship with Windows Phone, due in part to how the cellular provider restricts its service and how its network has been architected. Oh, there are other reasons, too. But, I'm keeping the soapbox stowed away today.
Case in point is a fantastic new app from Microsoft called Calls+.
Calls+ adds itself to the Settings area (not in the list of installed apps) for Windows Phone devices for Lumia's and non-Lumia's alike. It allows you to configure call waiting and call forwarding options, specific to your provider's network.
Unfortunately, it doesn't work for Verizon. Because I'm constantly testing and reviewing new smartphones, I keep accounts with T-Mobile and AT&T, while my company's corporate account is with Verizon. When I first installed Calls+ early this morning it was to the Verizon device. As you can see from the picture comparison, T-Mobile and AT&T support it just fine.
Non-Verizon customers can pick up the free app from the Windows Phone store here: Calls+