Would be using this to take notes with during the day, almost a Dictaphone.I haven't heard of any external mics for phones.. Most microphones are meant to do the basics.. Phone calls, videos.. They don't have a lot of range and tend to pick up quite a bit of static..
If you really need good audio get a digital camera + audio mic, then split the audio.. There's a lot of good microUSB mics for cameras such as GoPro.
or better yet get a USB microphone to use with a computer..![]()