I'm wondering which iPhone App would be the preferred method for recording input, or output, or both?

Can I use some iOS app running on the iPhone (I don't have an iPad) to record both a hardware output and a hardware input at the same time in, to two wavefiles (one input would be mono, the other output from software would be stereo)? Would be great to find this solution out, as our duo is battling buggy iPhone Apps on a secondary recorder device, consistently running out of battery on a preamp, etc.

We've only recently introduced the FireFace UCX into the mix and are hoping to finally get recordings of the mono input _and_ what comes out of the software.

How would we go about setting this up, please?

Thanks in advance!

Really love the FireFace. After purchasing a Mac in August 2009, I've gone through multiple soundcard, have hated all of them, and sorely missed my Multiface on the PC. After buying two soundcards last year and both being either overspecced+big+crashy stuttery audio, or underspecced,small,untrustworthy outputs/inputs and just feeling like the soundcard is possessed, getting the FireFace has been such a "why didn't I just take a loan and buy it in 2009" feel. I forgot how good RME can be. I'm absolutely chuffed at the LoopBack features and everything. I would've never believed a soundcard could offer that. So good!