Here is a measurement microphone for iPhone that makes life easier for audio engineers and technicians in live venues and recording studios. The MicW i437L Microphone has a Lightning interface. It has a 7mm capsule and an omnidirectional polar pattern with frequency response of 20Hz to 20 kHz.
The MicW i437L weighs only 1/3oz, measuring under 2″ long. It can be used for SPL metering, scratch track recording, and everything in between.[where to find it]