Help: Best iOS 5 SIMULTANEOUS Multitrack Recording App?

I recently purchased an Alesis IODock and love it!! It works great with Garageband, but, unfortunately, GB does not support simultaneous multitrack recoding, other than stereo input to a single channel. i.e. Input 1 -> Right, and Input 2 -> Left on a single track.

What I need is to be able to record Input 1 ->Track 1, Input 2 -> Track 2, and arm both tracks to record at the same time.

I have seen ads for various "Multitrack" apps in the app store, some VERY expensive, but none specifically say they can record to more than one channel at a time; some requiring iOS 7.

The other CRUCIAL issue with GarageBand, is that recordings are limited to just 32 minutes (320 bars). I record live music, currently using a MiniDisc deck with 80 minute discs. Which records great, but occationally band sets will go longer than 80 minutes, and I have to swap discs, trying not to miss anything the band wants recorded.

Is there a recording app that is only limited by the amount of available RAM on the iPad, AND is able to export an audio file that I can use on the Mac?

I can live with only recording stereo tracks, but multitrack is preferred.

Ultimately, I will be upgrading to more contemporary hardware, but at this time I am limited to iOS 5.1.1 compatability.

Any help, suggestion, advice, personal experiences.... would be greatly appreciated.

TIA