IK Multimedia's iRig MIDI 2 (US$99.99) is a universal MIDI interface for Mac and iOS. IK's original iRig MIDI was compatible with Apple's 30-pin dock connector, but not Apple's newer Lightning connector interface. The updated iRig MIDI now supports both connectors as well as USB for connecting to Mac.
I reviewed the original iRig MIDI back in 2011, so it's great to see a revamp of this portable MIDI interface. Features include a re-designed, smaller, pocket-sized form factor with a rubberized, sturdier enclosure, standard-sized MIDI ports, power provided from host device, detachable cables that are bumper / case friendly, and, of course, Lightning connector compatibility.
IK also offers a host of iOS apps to work with MIDI instruments. SampleTank Free is a comprehensive sound workstation with high-quality instruments and patterns. iGrand Piano FREE is a high-quality sampled grand piano. Finally, for Mac users, SampleTank 3 SE is a free desktop workstation with instruments and patterns. All apps can be upgraded with more sounds and features via in-app purchase.
The only downside to the iRig MIDI 2 is that it cost $30 more than the original iRig MIDI. However, with the improved features, design and higher-quality enclosure -- the original one was on the tacky side -- the iRig MIDI 2 should be a worthwhile investment for iOS MIDI enthusiasts.