Elastic FX is a powerful and intuitive 4-channel multi-effect processor for iPhone. Developed by Oliver Greschke, the app offers a wide range of options to shape and manipulate sound with its complex routing and effect selection.

With Elastic FX, users can connect to any input source, such as the device's built-in microphone, an external keyboard or guitar (requires an iPad soundcard), or even their favorite iOS drum machine or synthesizer via Inter-App Audio or Audiobus. Additionally, the app allows users to import sound files and apply up to 4 different effects simultaneously.

Featuring 4 effect units with various routing options, Elastic FX provides a comprehensive selection of 40 stereo effects across categories including modulation, pitch, distortion, filter, delay, reverb, and more. The app also includes a master effect section with level meters, a 3-band equalizer, compressor, and stutter fx.

One of the standout features of Elastic FX is the XY-Pad, which allows users to easily control the most important effect values in a Kaoss Pad style. Users can also automate and record XY-Pad tweaks, with options for 1, 2, 4, 8, or 16 bars length. In addition, certain effects, such as PingPong Delay, can be played in sync with Ableton Link/Inter-App Audio.

Elastic FX supports Audiobus 3, Audiobus state save, Audiobus remote control, and Inter-App Audio. It also includes a simple audio player for testing effects with audio files. The app offers the ability to tweak parameters via MIDI, with a MIDI learn option, and users can switch between user-presets using MIDI Program Change messages. Furthermore, users can save, load, and share their own presets.

With its array of features and versatility, Elastic FX is a must-have for musicians and audio enthusiasts looking to add depth and creativity to their iPhone music production.