The device is basically a compact audio interface that connects to the iPad, iPhone (or Android tablets/phones) via Lightning, the older 30 pin cable and micro USB and lets you record the output from a microphone, guitar or any other instrument using an XLR or 1/4” jack.
iRig PRO comes with various music apps like:
AmpliTube FREE (which is ultimate guitar and bass effects software, amp and recording studio for iPhone and iPad) including an additional 4 exclusive gear models (Metal W and Metal 150 amps, Wharmonator and X-Flanger stomp effects).
VocaLive FREE, the professional practicing, performing and recording vocal processor with 2 effects and single-track recorder, expandable to 12 effects and 4-track recorder (up to 8-tracks on VocaLive FREE for iPad)
SampleTank FREE, the ultimate virtual instrument and sound workstation featuring a complete expandable collection of instruments and effects and a few more very useful apps.
The iRig Pro can provide phantom power and has adjustable gain for maximum usability. At $149.99, it’s more expensive than several compact alternatives, but it’s the smallest iOS/Android compatible device that you’ll find.
Check the full list of available apps and features from IK Multimedia