Here is a stereo microphone that helps you capture better audio with your phone. The MOOU RHK26 iPhone Microphone has 2 x 180-degree rotatable mics and 3 modes. It is MFi certified and has a Lightning port that lets you charge your phone as you record. This condenser microphone comes with a key to adjust microphone volume.
The MOOU RHK26 has a 3.5mm mic interface. You can find out more about it here.