GrainProc vs PaSSBot
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
GrainProc
Create unique sounds and musical textures in real-time by processing external audio. This app features two parallel granular engines for layering sounds, offering a versatile tool for musicians and sound designers.
- Real-time granular synthesis
- Two parallel grain engines
- AudioBus input support
- Waveform sound source manipulation
- Control over volume, feedback, and density
- Visual level monitoring
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GrainProc is a real-time granular synthesizer with which you can create new sounds and musical textures by affecting your voice, your instrument, or any input from AudioBus. 2 grain engines run in parallel, allowing you to layer two sounds and create rich textures, even as a solo performer! Features: • 2 Granular synthesizers running in parallel • Waveform representation of the sound allowing you to touch where you want the sound source to be • Sliders to control dry volume, wet volume, feedback level, and grain density • Visual level monitors of the dry, wet and feedback levels • Simple enough to be used with your feet! We discourage using your device with your feet, though it has been used that way for public performances!
PaSSBot
This app is a stochastic filter bank audio processor for iPad, offering advanced sound manipulation with various filter types and powerful stochastic generators. It allows for precise control over filter parameters and harmonic distribution, ideal for creating complex audio textures.
- Stochastic filter bank audio processor
- Multiple filter types (Biquad, Ladder, SEM, Resonators)
- Up to 64 filters in stereo
- Powerful stochastic generators
- Individual filter parameter control
- Harmonic distribution options
- Precision DSP rendering (<1ms control rate)
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PaSSBot is a unique stochastic filter bank audio processor. The desktop VST/AU version of PaSSbot has already arrived in February 2020 and this iOS version is equivalent to the latest version 2.1. PaSSBot filter types are Biquad, StateVariableFilter, Ladder, SEM and Resonators. With behaviors of bandpass, Lo + Hipass, Notch and up to 64 of them in true stereo ! The user can set values of center frequency, gain and resonance of the each filter, which will be then eloborated with powerful stochastic generators ( 4 independent GENs for each filter ) with continuous or discrete probabilistic distributions but also with standard waveforms. One can set each filter parameters individually, but also distribute them in harmonic order, again the harmonic spread ratio can be set by the user or even can be modulated by a GEN. Precision DSP rendering, less than 1milisec. control rate precision. The filters can run continuously or be triggered manually. In that case, each filter will be applied an independent AR envelope with configurable random duration. Important notes : - A recent iPAD model is being recommended and also setting the host buffer size to 128 or higher greatly helps to the CPU needs which also heavily depends on the number of parallel filters being used. - The resonators can be sensitive to input signal level. - The PaSSBot manual can be found at this link. https://www.sonic-lab.com/PaSSBot_files/PassBot_manual.pdf sonicLAB PaSSBot youtube playlist : https://www.youtube.com/playlist?list=PLP0cOkraQHDYUoMG6BETTN1eGm-Kq5z0T
Screenshots
Verdict
The clearest difference is price: GrainProc at $2.99 against PaSSBot's $34.99. PaSSBot's advantage is rating (5.0 vs 4.2) and review sentiment (100% vs 60%). On ratings volume, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
GrainProc costs $2.99 and PaSSBot $34.99 up front. Neither carries in-app purchases, so what you see is what you pay.
PaSSBot holds the better App Store score, 5.0 against 4.2. Both are backed by a comparable volume of ratings — 18 and 8 respectively. Written reviews point the same way: 60% of GrainProc's written reviews are positive against 100% of PaSSBot's.
GrainProc ships an update every 2 months, PaSSBot every 4 months. Both last shipped on October 23, 2026.
| Parameter | GrainProc | PaSSBot |
|---|---|---|
| Price | $2.99 — better | $34.99 |
| Rating | 4.2 (18 ratings) | 5.0 (8 ratings) — better |
| Positive reviews | 60.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 18 — better | 8 |
| Update frequency | Every 2 months — better | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad — better | iPad |
| Requires iOS | 16.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 11 MB |
| Age rating | 4+ | 4+ |
| Developer | Mayank Sanganeria | SonicPlanet Audio Video Teknolojileri Anonim Sti. |
Customer experience
GrainProc
PaSSBot
In-app purchases
GrainProc
No in-app purchases
PaSSBot
No in-app purchases









