There are other compact class-compliant audio interfaces that can convert analog 3.5mm stereo to digital Lightning input (iPhone or iPad), although not as pocketable as that Sonicport. I use a MOTU Microbook IIc interface for gigs, usually with laptop, keyboard, etc. However, I have also used it as stereo or multi-track recorder to my iPhone running AUM as mixer/recorder. It can simultaneously record 1/8" stereo mic input, plus one phantom-powered mic, plus one line-level input plus whatever sound-generating app(s) I have running on the iPhone, each recorded into separate WAV files. To do all of these inputs with iPhone alone, it requires powering the interface, since the iPhone cannot provide enough power (the laptop can, of course). The MOTU Microbook is a little bigger than the iPhone, but still makes for a very compact rig, with excellent A/D and D/A converters. Easy to export the WAV files from AUM to stack in your multi-tracking audio application of choice. The Microbook also has a headphone out, so you can monitor as you record. AUM allows you to create a mix buss for headphone out, as well as controlling record levels of all of the inputs, adding effects, limiter, EQ, etc.