XT Software recently released energyXT for iOS. The application does both audio recording and drums/synths (like a mini audio/midi sequencer) all in one single view. It's compatible with iPhone, iPod touch, and iPad and costs $9.99.

With energyXT for iOS you can arrange your recordings in verse, chorus, intro, etc. When you've recorded something you like, export it to your Dropbox account in one click, either as mixdown or as one-audio-file-per-track, for import in to your favorite DAW.

Features:

• Samples provided by www.loopmasters.com.
• Three main views for arranging, recording and editing.
• Unlimited tracks. 4 types: Drum, Synth/sampler, Chord and Audio (voice/guitar).
• Live playback and recording with multi-touch.
• Send your mixdown or multi-track project to dropbox with one click, and then import in to your DAW.
• Pattern based arrangement (intro, verse, chorus etc).
• Multi-track audio recording with "multi-take" option.
• Unlimited undo and redo.
• Drum sampler with filter.
• Synth/sampler with vol, pan, envelope, filter, chorus and delay.
• Playback and record chords with 'drum pads'.