I’ve been looking for ways to make glitch art on the iPad using buggy apps as opposed to databending (yes, there are hex editors available for iPad!) or glitch apps.
So far the Autodesk 123D series of products has stable glitches that produce exploding meshes (123D Sculpt) and z-fighting (123D Design).
Z-fighting can be intentionally produced by creating coplanar surfaces (primitive polygons work best) that occupy the same space and contain different colors or lighting conditions. The z-buffer interference patterns will vary depending on the rendering environment used.