What kind of "sound app"? What are you wanting to do?
An iPad may be a great tool for setup and some simple operations but is probably not the right tool to provide acceptable quality, flexibility and reliability in regards network, control, audio, etc. connectivity for critical applications.I'd love something like what's being described-- simple sfx cuing for the iPad that allows for things like individual track envelope and pan, individual track start and stop times, toggling auto advance, etc. Seems like a no-brainer, in that simple sound playback and transport controls are well within the iPad's processing capabilities and its size and touch UI make it preferable to dedicating a laptop that's probably way overpowered for the task at hand. Something possibly like Macs Cue, tailored for iOS. I'm actually surprised no one has stepped in to make this product (well, aside from the fact that the market is relatively small compared to, say, Angry Birds