MIDI Sliders is a free iPad app that sends MIDI control messages via USB (connected through the Camera Connector) or to a Mac via WiFi. A simple, intuitive interface requires almost no setup.
Almost all MIDI signal types are supported. For MIDI Controller messages, the lower numbered Controllers (0-31) are automatically chained with their "least significant byte" controller (32-63), for 14-bit resolution. Each slider sends data on its own MIDI Channel (1-8).
And for fun, we have added:
+ 2 other kinds of "sliders" display modes
+ an audio test tone function
+ shake/knock the iPad to nudge all sliders at once
NOTE: To avoid accidentally swiping-out of MIDI Sliders, it is recommended to TURN OFF "MULTITASKING GESTURES" in your iPad's Settings.