Cell phone video is pretty good now. What’s not good is the built in mic on your cell phone. The good news is that it doesn’t take much to upgrade the audio for your video. This inexpensive Rode mic will definitely do the trick. To add this you will need a special case or cage with a cold shoe to mount this to your cell phone. Good news is that it is cheap. Take a look at the Amazon links below for more information
*These are only suggestions. There many choices you could make in any of these product choices. Research to see what would be best for you.