# Auto Fills Drum Fill Generator — Generative AUv3 MIDI Sequencer

> Generative AUv3 MIDI sequencer for creating random drum fills. (iPhone/iPad app by Cem Olcay.)

- Source: https://appshunter.io/ios/app/auto-fills-drum-fill-generator/id6476319733 (this page in markdown: same URL + `.md`)
- Developer: [Cem Olcay](https://appshunter.io/developer/523633853)
- Category: Music, Utilities
- Price: $5.99
- Rating: 4.50/5 from 20 App Store ratings · 15 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 20 MB
- Languages: American English
- Released: 2024-02-02
- Data updated: 2026-08-29
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/auto-fills-drum-fill-generator/id6476319733/reviews.md

## What is Auto Fills Drum Fill Generator?

Auto Fills is a random MIDI generator app for creating drum fills for your drum synth apps or hardware synthesizers. It works as an Audio Unit AUv3 plugin with the supported host apps such as AUM, Loopy Pro, Logic Pro, Cubasis, Nanostudio, apeMatrix etc. 

In Auto Fills, you are working with a drum kit. You can either create the kit by adding drum parts and assigning them MIDI notes/channels yourself, or you can select a kit templete from the settings menu for an app or hardware for quick setup. 

- In Kit mode, you can assign a probability value to each drum part. 
- In Velocity mode, you can assign a velocity to each drum part, and you can also introduce velocity variety for them. 
- In Duration mode, you can set the drum fill length as well as the waiting time before and/or after the drum fill, in beats or bars. 
- If you've set "wait before the fill" and/or "wait after the fill" durations in the Duration mode, the drum fill won't be played during the waiting periods. 

If you have a favorite drum sequencer, you can route it through the Auto Fills, before the drum app, like
- Drum sequencer -> Auto Fills -> Drum App

And you can block the incoming MIDI from the drum sequencer during the drum fill.
You enable the option in the Duration mode by toggling "block incoming MIDI during the fill" option. 
You also have an option for randomizing the drum fill on every cycle.

Assigning probability values is crucial in the Kit mode. If you want to hear a specific drum part mode, just increase it's probability. If you would like to hear a drum part less ofter, just decrease its probability. If you set a probability to zero, it won't play in the drum fill. 

- Density knob leaves out notes from the drum if you decrease  its value. It introduces rests in the drum fill without regenerating the fill.
- Voices knob sets the maximum number of drum parts can be played at the same time (polyphony). The algorithm chooses a value between 1 and the maximum voice count randomly on every step of the drum fill.
- Rate note sets the speed of the drum fill. 
- Generate button lets you regenerate the drum fill. Changing the kit by adding/removing parts, probabilities and voice count also regenerates the fill automatically. 

Auto Fills is a MIDI app and it does not produce it's own sound. You need to route Auto Fills MIDI out to an audio app's MIDI input in order to hear the voice.

## Key features

- Random MIDI drum fill generation
- Customizable drum kits with note/channel assignment
- Probability-based drum part selection
- Adjustable fill duration and timing
- Velocity and density controls
- AUv3 plugin integration with host apps

## Recent user reviews (10 of 15)

All indexed reviews: https://appshunter.io/ios/app/auto-fills-drum-fill-generator/id6476319733/reviews.md

### 2/5 — Good idea… poor execution …and room for improvement

*2026-06-26*

This app could be greatly improved

   Ui needs to be fixed for iPad as the knobs are WAY too small to fiddle with
 They are microscopic on the iPad and hard to adjust…I would love it if you could sequence the “duration patterns”. This would make this a 5 star must have utility

**Developer response:** AUv3 parameters are exposed! <3
Edit: troll - don’t take it serious

### 3/5 — Useful…and room for improvement

*2026-04-09*

Good app
   I would love it if it could sequence the “duration patterns”. This would make this a 5 star must have utility

**Developer response:** AUv3 parameters are exposed! <3

### 5/5 — The  1, and the only one

*2026-03-09*

This is another superb app brought to you by one of the best developers out there. So easy to set up, and once you hit play you’ll wonder where this app was your entire life.

### 5/5 — Fills!

*2025-08-05*

Perfect for apps that don’t have fill functionality like AR909

### 5/5 — The only of its kind 👍👍👍👍👍

*2025-08-02*

I was super greatful when Auto Fills came out. It definitely made drum sessions easier. It’s one of a kind

### 3/5 — Almost What I Needed

*2025-03-22*

I’d like to manually trigger the fill but have the fill end on beat one of the following bar. From what I’m seeing now, the manual mode triggers the fill for the selected duration but bleeds into the next bar unless you would trigger the fill exactly on the correct beat. I like to trigger the fill manually at any beat and then have the fill last until beat one of the following bar, preferably with an option to add crash cymbal on beat one. I own other drum apps that do this. It is great for live performance because you can determine when and how long every fill occurs. Would love to see this in an update. Thanks.

### 5/5 — A perfect addition

*2024-10-01*

It’s true, there’s nothing that “fills” this spot in the midi sequencing tool shed. Intuitive and powerful. Responsive and supportive development, what more can you ask for, get it!

### 5/5 — Exactly what the Drum Dr. ordered

*2024-09-19*

I have struggled for years with drums, particularly fills. This app is a game changer for my drum workflow and the only thing like it out there. I absolutely love it and use it on every track. I never thought someone would be so creative as to just address writing fills, but this developer is really amazing.

### 5/5 — Woah!

*2024-08-09*

Cem is legend for this one.  Yeah, I know the bud apps are brilliant, but name another fill app with this kind of power.  My next Cem app will be loop bud. Thats how much Cem’s creations inspire us.   We can’t get enough, I certainly cannot.

### 3/5 — More Bud quirkiness

*2024-03-01*

So, previous bud apps you can export midi pattern to Files but this one not. No decent documentation or tutorials by this dev. At best you get maybe a 50 second video with no explanation.

**Developer response:** Hi, you can export MIDI, the option is on the settings menu :)
There are plenty of tutorial and review videos on youtube for this app. Also there’s a quick tutorial section you can find on the settings menu as well.

## Frequently asked questions about Auto Fills Drum Fill Generator

### What is Auto Fills?

Auto Fills is a generative AUv3 MIDI sequencer designed to create random drum fills for drum synths and hardware. It functions as a plugin within compatible music production applications.

### How does Auto Fills generate drum fills?

You can create custom drum kits by assigning MIDI notes and channels to drum parts, or use pre-set templates. Probabilities can be assigned to each part to influence their appearance in the generated fills.

### Can I control the timing and length of the drum fills?

Yes, Auto Fills offers a Duration mode where you can set the fill length and the waiting time before and after the fill, measured in beats or bars.

### Does Auto Fills produce its own sound?

No, Auto Fills is a MIDI app and does not generate audio. You need to route its MIDI output to a separate audio app or hardware synthesizer to hear the drum sounds.

### What is the price of Auto Fills?

Auto Fills is a paid application, priced at $5.99. This is a one-time purchase and does not involve subscriptions or in-app purchases.

### What devices is Auto Fills compatible with?

Auto Fills is available for iPhone, iPad, and iPod. It requires iOS 4+ and is designed for mobile music creation.

### How often is Auto Fills updated?

The app was last updated on September 30, 2024, indicating active development and support. The latest version is 1.8.1.

### Does Auto Fills have ads?

No, Auto Fills does not contain advertisements. As a paid application, it offers an ad-free experience for users.

## Version history (last 5 releases)

### 2.1 — 2026-08-17

This version modernizes the Auto Fills
- Adds builtin drum sampler to the standalone app.
- Updates the audio and midi engine.
- Improves the sample-accuracy.
- Improves the performance of the AUv3 plugin.
- Adds online user manual to the settings menu.

### 2.0 — 2026-08-15

This version modernizes the Auto Fills
- Adds builtin drum sampler to the standalone app.
- Updates the audio and midi engine.
- Improves the performance of the AUv3 plugin.
- Adds online user manual to the settings menu.

### 1.8.1 — 2024-09-30

This version adds new hardware template for Elektron Rytm.

### 1.8 — 2024-09-02

This version updates the support section on the settings menu.

### 1.7 — 2024-07-10

Fixes the reloading bug happens when changing the patterns.

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## More apps by Cem Olcay

- [FretBud - Chord & Scales AUv3](https://appshunter.io/ios/app/fretbud-chord-and-scales-auv3/id1234224249)
- [ScaleBud - AUv3 MIDI Keyboard](https://appshunter.io/ios/app/scalebud-auv3-midi-keyboard/id1409125865)
- [StepBud - AUv3 MIDI Sequencer](https://appshunter.io/ios/app/stepbud-auv3-midi-sequencer/id1453104408)
- [RhythmBud - AUv3 MIDI FX](https://appshunter.io/ios/app/rhythmbud-auv3-midi-fx/id1484320891)
- [ArpBud 2 AUv3 MIDI Arpeggiator](https://appshunter.io/ios/app/arpbud-2-auv3-midi-arpeggiator/id1500403326)
- [ChordBud 2 AUv3 MIDI Sequencer](https://appshunter.io/ios/app/chordbud-2-auv3-midi-sequencer/id1526221230)

All apps by Cem Olcay: https://appshunter.io/developer/523633853

## Related topics

[cem olcay](https://appshunter.io/ios/topics/cem-olcay)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*