DP Control

Another controller, this time from Motu for their Digital Performer, and it is free. Here's what the app does:

DP Control from MOTU Inc. allows you to control MOTU's Digital Performer audio workstation software over a WiFi network using your iPhone, iPad or third-generation iPod Touch.

Built specifically for use with Digital Performer, DP Control gives you easy access to the most important transport and mixer functions for tracking, simple mixing, and live performance.

DP Control works in both portrait and landscape orientations. Designed with comfortably large buttons and controls, DP Control can easily be used with only one hand by pressing buttons and swiping to new pages with your thumb.

Feature highlights:

• Real two-way communication — everything that you update in DP updates in DP Control, and vice versa.
• Editable time counter with selectable format (including real-time, SMPTE time, samples, and marker names).
• Main transport control and many other transport-related Control Panel functions (click, countoff, memory-cycle, etc.)
• Page-controlled, scrollable mixer with animated, recordable pan knobs and volume sliders, plus level meters and peak indicators.
• Solo, Mute, Record-enable, Play automation, Record automation and automation mode settings for each track.
• Track list for your DP project, complete with collapsable nested track folders and dynamically linked track organization that matches your currently open DP project on your Mac.
• Infinite undo, with a view that shows you the names of the next and previous tasks in your DP document undo history.
• Marker creation and naming.
• New Take, Previous Take, and Next Take functions that operate on all of the record-enabled tracks at once (essential for tracking drums).
• Take selection, by name, for individual tracks. Also New Take, Delete Take, and Rename Take for the current take on any individual track.
• Save function for saving changes made to the DP document.

Requirements:

• Compatible with iPhone, iPad, and third-generation iPod Touch
• Not compatible with first or second generation iPod Touch
• Requires Digital Performer 7.2 or later running on a Mac on the same WiFi network as DP Control