# SL Knock vs Tracker Pro

The clearest difference is price: SL Knock at $6.99 against Tracker Pro's $14.99. SL Knock also leads on iOS requirement (15.0 vs 17.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

SL Knock costs $6.99 and Tracker Pro $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on November 10, 2026 and November 14, 2026 respectively.

## The numbers

| Metric | SL Knock | Tracker Pro |
| --- | --- | --- |
| Price | **$6.99** | $14.99 |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/tracker-pro-sampler-and-synths/id6812401572/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | Weekly |
| Monetization | — | Paid |
| Size | 29 MB | 47 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 17+ |
| Developer | [VIACHESLAV ZHILTSOV](https://appshunter.io/developer/1862005860) | [Dubspot](https://appshunter.io/developer/6812401574) |

## What reviewers say

### SL Knock

[App page](https://appshunter.io/ios/app/sl-knock/id6797349065)

**Features:** macOS Compatibility, Vision Pro support, iPhone Duo support

**In-app purchases:** none


### Tracker Pro

[App page](https://appshunter.io/ios/app/tracker-pro-sampler-and-synths/id6812401572)

Create music with samples, synthesizers, and Audio Unit plugins within a pattern grid. Arrange patterns into songs, shape sounds with commands, and utilize touch, keyboard, or MIDI input. Includes built-in sounds and a demo to get started.

**Highlights:** Pattern grid for music creation, Integrated samplers and synthesizers, Audio Unit (AUv3) plugin hosting, Advanced step sequencing with commands, Song arrangement and structure, Multiple input methods (touch, keyboard, MIDI), Export mixes and individual stems

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is SL Knock free?

SL Knock costs $6.99, with no in-app purchases.

### Is Tracker Pro free?

Tracker Pro costs $14.99, with no in-app purchases.

### Do SL Knock or Tracker Pro have ads?

Neither SL Knock nor Tracker Pro shows ads.

### Which is updated more often, SL Knock or Tracker Pro?

SL Knock ships an update weekly, and Tracker Pro weekly. Most recently, SL Knock was updated on November 10, 2026 and Tracker Pro on November 14, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*