Developer Wooji Juice has introduced Hokusai – a free multitrack audio editor for iPhone or iPad:

Record or import a track, and make it sound the way you want it to: not just trimming the ends, but full cut, copy, paste and delete, and a suite of filters and special effects available.

Edit many tracks side-by-side, mix them together, and export to wave or mp4 format — then transfer them to your computer via USB or Dropbox, or send them to another app on your device.

Hokusai is streamlined to give you a clean, clear view of your tracks. Use the familiar pinch and swipe gestures to zoom right in and fiddle with fine detail, or step back to see the big picture. And just like selecting text in other apps, you can select pieces of audio. Live “scrubbing” means you can hear the sound under your fingertip as you make your adjustments. And you needn’t fear a bad edit with our full undo/redo support: as many levels as space allows.

Hokusai comes free with a set of useful tools such as fade in/out, normalise volume levels, reverse time, and basic synthesis. If you need more power, though, you can upgrade from inside the app to add new tools and effects, including:

• AudioCopy/AudioPaste
• grain synthesis
• noise gating
• time-stretching
• pitch-bending
• echo
• reverb
• modulation (AM & FM)
• resonance
• distortion
  grunge
• vocal levelling
• monster voice
• high/low/band-pass/notch-cut filter

It’s available now in the App Store.