Rmpx4 is a multi effect processor focused on modulations. Based around three classic effects (multimode filter, pitchshifter and delay), its aim is to generate evolving variations of the input audio by crossfading between two instances of each effect and modulating their key parameters using an extensive array of control modules. 4 LFOs with optional tempo sync and 2 envelope followers can have their output inverted or combined using mixers and multipliers.
Price: 20€ for the Mac and PC versions. There is an the introductory price of 10€ until January 12, 2014. The Linux version is free of charge.