You're having a problem with
gain staging, obviously. That link is where I learned how to finally get all that under control running through a huge signal chain. But your situation is much simpler. Seeing as how the iRig interface is getting hit with peaks, even with it's gain as low as possible, that means you're going into the interface too hot.
So you either need to come down on the pickup gain on the guitar itself, or if you're running through pedals and THEN hitting the interface, you have a problem there. Somewhere along the line between your guitar, compressor, equalizer, distortion pedal, etc... you're running too hot. The easiest fix would be to reduce the gain the last pedal in your signal path, or with no pedals then to turn the volume knob down on the guitar.
The iRig works fine, is my point. It's a user error issue related to recording levels.
