Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.
Download on the App StoreAudiobus is the app that makes the rest of your setup better.
Turquoise DS on the Bus!
Nice little update I discovered last night 
Comments
https://itunes.apple.com/us/app/turquoise-ds/id606674241?mt=8
What's up with the load rec button? Doesn't seem to be working for me.
Turquoise DS on sale right now for $2.99 - it is usually $4.99, though it appears it was free for a brief time a few months back.
Is this thing any good? I've been swinging and missing a little on some cheap/sale synths and drum apps recently.
FWIW I downloaded it for free and deleted it shortly after. I'm picky about the feel of pad type apps and I didn't like the response playing the pads. I've been spoiled by the feel of the pads of Easybeats 3 and ChordPolyPad which are my personal favorites. YMMV
@yowza said:
100% agree on both of those 2 apps you cited as examples of touch pads that work very well!
Thanks for the input on Turquoise. Don't think it looks bad, but not special enough that I need to snap it up.
I'm a little curious about this issue of pads in certain apps not responding as well as those in other apps... although I can't recall at the moment what app it was (that I have since deleted) that had this problem. Weird - how does one explain why one dev can pull this off beautifully while another can't. Skill set? The way a particular app functions?
Some apps have a great sound and I use them as a sound module and control via MIDI from other apps but I can't stand playing the pads, the FM synth TF7 comes to mind. Great sound but I don't like the pads at all although they aren't really pads, more like square keys.
Apps where I typically like the pad response are the ones that allow you to slide your fingers across the pads and the sound is triggered the instant you reach the pad's border (ala Thumbjam, Drumjam, EasyBeats 3, ChordPolyPad). The apps where I typically don't like the pad response are the ones where you have to lift your fingers off the glass and tap each pad and the sound is only triggered with each discrete tap like the aforementioned TF7.
I guess it depends on which approach each dev uses.
I think it's a lot of things relating to optimization. Beat Machine is a promising app, but the whole thing is so laggy overall that the pads don't respond, or at least not on my older device. He is working on a pretty substantial update, however, so that may be addressed soon.
I have no problem with DS pad response at all. Some of the presets have a fair amount of attack applied but this is easily tweaked and saved. This is a very deceptive app imo and is excellent for constructing loops or sound effects. Well worth the dollars.