Warning (Not a replacement for an H4n or Sound Devices - just another use for your phone) Warning
The iPhone uses a Mono mic input on a TRRS connection, so I was wondering what other mics you could use with the iPhone. Snag a good enough mic and you have yourself a solid portable recorder on the go.
Check this out:
Its an XLR to TRRS adapter.
Now grab this if you want to use a shotgun mic:
http://www.bhphotovideo.com/c/product/242696-REG/Audix_APS_911_APS911_Phantom_Power_Supply.html
And for 60 bucks you now have the option to throw a couple pieces of gear into your backpack and have the ability to whip out your phone with your favorite mic to record away!