Fluss - Granular Playground 4+

Tactile Granular Synthesizer

Bram Bos

    • $13.99



Fluss is a sonic playground designed by Bram Bos and Berlin-based musician Hainbach to let you explore granular synthesis in a hands-on way. The playful touch UI invites anything from live performance, experimentation to learning and mastering the granular concept.

Multiple plugins: Import, Record or Live Process
You can import your own WAVs (standalone & AUv3 Instrument plugin), Record audio (Record effect plugin) or live-process sound (Process effect plugin) to create anything from drones and granular echoes to moving microtonal audio textures.

Designed for touch: Kinetic Sliders
All sliders and XY pads are linked to a physics model which lets you flick and throw them around. Minimise the friction for endless bouncing motion, as an innovative substitute for traditional LFOs and modulation. There was never a better reason for using a touchscreen for music.

Shimmer Feedback effect
Like a shimmer reverb, except it feeds the processed audio back into the grain engine. This lets you create an endless loop of pitch-shifting spaciousness, turning even the simplest of sounds into massive woolly mammoths.

- 3 Voice grain engine, each with an independent playhead
- Playable via MIDI (since version 1.1)
- Filter inspired by the Oberheim Xpander, including its resonant Phase filter
- Kinetic sliders and pads for playful interaction with the sound
- Universal design (iPhone and iPad; iPad Air 2 or higher recommended)
- Custom scales, unquantised mode and even Scala-import for microtonal experiments
- Use WAVs (or other audio files), record audio or load the app as a live-processing audio effect
- Real world tested as an instrument in numerous live performances by Hainbach
- Offers light mode and dark mode UI

What’s New

Version 1.1

Fluss is now playable via MIDI!
- Load Fluss as an AU instrument and you can play the grain engine like a 3-voice synthesizer
- Switch to MIDI mode in the "scale window" (or simply start sending MIDI notes)
- Envelopes for the MIDI notes are derived from the current settings of the grains (i.e. grain window, grain size, density) so the character of the notes matches the character of the grains

- AU Parameters also accessible directly via MIDI CC (for hosts that don't support AU Parameters)
- Record button exposed as an AU parameter - for MIDI learn in AUM etc.
- Freeze-hold function exposed as an AU parameter - for MIDI learn in AUM etc.
- Preset Batch Export function replaces Backup folder in Files
- More robust Scala import (more resilient against invalid/malformed files)
- Success message will be displayed when importing a Scala file

Ratings and Reviews

4.8 out of 5
39 Ratings

39 Ratings

pj4533 ,

Very Fun!

Overall, this is an amazing implementation of granular synthesis. Fluss is very fun to use and the integration with the touch interface toward modulation is particularly innovative. That said, the more I like it, the more I want Fluss2!

Specifically, I would love more clock and tempo syncing options, particularly around when grains are triggered (like on Beads). But also, when using Fluss as a processor, some more visualization of the buffer, playback head speed, and modulation, in terms of tempo rather than time.

The quantizer also begs for more visualization. I’d love to see the boundaries shown in the XY control for notes! And if that gets too keyboard-y and not Buchla enough, you could make the boundaries into shapes, or even allow the user to change the layout to keep it super creative. Basically keeping the fun randomness, but allowing for a biiiiiit more control, when desired.

Further, while the touch interface is very innovative, I found it a bit sensitive. Very easy to cause the controls to move too fast. You can use the friction control to slow things down, but that seems to slow everything down. Would be nice to have a global friction and a separate sensitivity option so flicking a slider could only apply a maximum amount of force.

Lastly, being able to apply modulation to a specific play head would be huge. So one head could be making bigger grains and another smaller, for example.

Well done!


Another Great 😊 Bram

Super fun makes a granular not so daunting. To the guy who reviewed saying you can’t sample just load it into a effects slot in AUM if that’s your choice like me. It can sample any auv3 app if loaded into effects and make sure to choose fluss recorder au. That’s all I got for now. Well worth the price imho ! Keep on keepin on guys!

Pookie Pants Stank ,

It could be perfect, but not quite there yet

Fantastic fun music app - such an idea generator! My biggest complaint is twofold: 1. You can’t SAMPLE.. yet this is supposed to be a granular sampler. Having to load wav files from your iOS File explorer is a pain and should be an option. Please add a “sample” button that activates the microphone on your iOS device (see Andrew Huang’s “Flip” for reference). 2. There needs to be preset browser arrows to page through your presets without having to open the pop-up browser window. Fix those two glaring issues, and you’ll have a 5-star review. Even if you don’t make a proper desktop version for your DAW.

Developer Response ,

Hi there! Thanks for the review! You can already record your own sounds into it if you load the "Fluss Recorder" AUv3 plugin in an effect slot of your host. This will let you record all incoming sound (the record button will appear next to the waveform viewer).

App Privacy

The developer, Bram Bos, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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