I had a great question from Artem about connecting a 3 pole microphone to his iPhone 7 using the headphone to Lightning adapter cable. The answer is yes, you can. You just need the ETG-003 3-pole to 4-pole adapter.
Check out the video to see how easy it is to connect a microphone and to hear that it actually works!
ETG-003 3-pole to 4-pole adapter: http://www.edutige.net/shop/etg-003-3-pole-4-pole-microphone-adapter/
ETM-001 microphone: http://www.edutige.net/shop/external-microphone-for-gopro-hero4-or-dslr-etm-001/