O-G-SUS (Oliver Greschke) is already well known amongst iOS musicians for the excellent Elastic Drums app, but his latest offering is an effects app: Elastic FX.
Kosmonaut is Bram's take on a delay effect. Like Troublemaker and Ripplemaker, the GUI is both a cool design, easy to use in the compact mobile format and packed with features.
Flux FX is an ambitious iOS effect processor created by guitar legend Adrian Belew and developers. It provides a chain of up to five versatile effects, each with an X-Y pad for performance access, plus a step sequencer for capturing pad motion.