cellsDS is a free programmable grid-based music sequencer for the Nintendo DS.
Description:
cellsDS is six sequencers in one, with each sequencer being controlled by a user definable Lua script. It is the peculiar anti-social stepchild of the Tenori-On and Monome.
Features include:

Dead simple user interface.
Ability to create your own unique sequencer rules using the Lua programming language. [...]

GlitchDS is a free cellular automaton music sequencer for the Nintendo DS that could be great for creating IDM and Glitch style loops. 
Features include:

Customizable Cellular Automaton sequencer
Create your own “trigger points”
Load in your own sounds
Save and load your work
BPM settings, or “strum mode” for controlling tempo
Up to 6 sounds can be loaded at once
Each sound [...]