Maybe it is a surprise for you when you noticed you can use FM radio on Moto G. Nowadays, most smartphones do not provide FM radios anymore. This guide teaches you how to use FM radio on Moto G, and some tips and tricks of using FM radio on Moto G.
If you cannot find the FM radio app on your Moto G, you can install the app from Google Play Store here: Motorola FM Radio. Of course, it is free. The version of this app on Google Play store is newer than the stock one. So, even you can find the app on your Moto G, you may try to update it to Google Play one to get all features and achieve the best performance.
Once Motorola FM Radio app is installed on your Moto G, you can start to use FM radio on Moto G just like any other apps.