It has been a while since Microsoft removed the official FM radio app from windows phone. A lot of people complained about it as the stock FM radio app on the Lumia and other windows 10 mobile devices was working just fine. Another reason why so many people were complaining about the removable of FM radio app is the fact that all the apps available on the store were either paid or have advertisements inside the app which can ruin user experience.
The stock radio application did not have any advertisements and worked like a charm. Nevertheless, there is an paid FM radio app for Lumia 950 that does not requires any tinkering with the registry. One really amazing feature is fact this FM radio app also supports loudspeaker.
Keep in mind that even if you switch to loudspeaker, you will still have to plug in your headset because your phone uses it as antenna. You can buy the app for about a dollar from Microsoft store.
Some users are saying that this app only picks up FM channels that have excellent reception. So, if your favorite one does not have flawless reception, you are out of luck and it won’t play them. The developer should change name for non-Chinese users. As I know there is possibility to show different name of app depending of phone language. And it crash sometimes, usually when I want to choose station from my favorites. You could also add black color scheme.