There are so many features packed into the devices we buy today that some people may never learn them all before upgrading to a newer one. Most of the time this is from the user not going through the features that are made available to them. Sometimes, though, there are features built-in that aren't exposed to the user for one reason or another. Some LG devices have an FM radio application pre-installed while others can sideload the application to gain the same feature.
However, there's a secret audio recording option that users can gain access to if they know what they are looking for. To help people figure this out, XDA JonnyTrulove, Member has put together a how-to guide for the LG V30 that shows you exactly how it is done. Once you have the working FM Radio application from LG installed, then you can use the free (via APKMirror) or paid version (via the Play Store) to create a shortcut that gives you access to the hidden audio recording feature.