The Shure MV88 is a microphone made specifically for lightning based iPhone, iPad, and iPod mobile devices. Despite its small size, it produces impressive sound quality and proves quite flexible with its four polar pickup patterns for different situations: Stereo with adjustable width, cardioid, bi-directional (figure 8), and mid side stereo. These patterns equip you to record in a variety of situations including live music, VLOGs, podcasts, and ambience for films.
To decode mid side stereo recordings, you'll need a decoder plugin. I use Voxengo MSED (free plugin to decode mid side recordings).