In order for NextRadio to use the FM receiver chip in smartphones and tablets, a specific software component needs to be present in the Android operating system. This is known as the FM hardware API (Application Programming Interface).
Typically, device manufacturers do not include FM support unless the wireless carrier requests it. Sprint and AT&T have done this.
HTC is an exception. HTC includes FM support in several of their devices regardless of wireless carrier. That's why the NextRadio app works on these devices even when purchased from carriers that have not yet partnered with NextRadio.
The HTC One M8 shipped from HTC with Android 5 Lollipop installed. Recently, HTC and wireless carriers updated the M8 to Android 6 Marshmallow.
NextRadio works on Marshmallow. We adhered to Google's Marshmallow compatibility guidelines, and worked with device manufacturers to ensure the app performs well.
Unfortunately, when Verizon pushed the Marshmallow update to their M8 phones, they appear to have removed the FM hardware API, so NextRadio is no longer able to control the FM receiver chip. Several other carriers also sell the M8, and have also updated them to Android Marshmallow. NextRadio still works on the M8 sold through all carriers except Verizon.
The FM API can't be included in the NextRadio app, and it can't be added back once it has been removed. So there is no way to restore NextRadio support to Verizon's M8s.
We are working to get all device manufacturers and wireless carriers to include FM radio support on all devices. Visit http://freeradioonmyphone.org/ to see how you can contact Verizon and let them know you want FM radio on your phone.