# BYK Additive Guide vs PSSI

The clearest difference is update cadence: PSSI at every 2 days against BYK Additive Guide's every 4 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

BYK Additive Guide ships an update every 4 months, PSSI every 2 days. The most recent releases landed on October 14, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | BYK Additive Guide | PSSI |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 70.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 days** |
| Monetization | Free | — |
| Size | 15 MB | 135 MB |
| Requires iOS | **16.6** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [BYK-Chemie GmbH](https://appshunter.io/developer/423808350) | [Evan Richardson](https://appshunter.io/developer/1727360047) |

## What reviewers say

### BYK Additive Guide

[App page](https://appshunter.io/ios/app/byk-additive-guide/id423808347)

Explore BYK's additive portfolio with this app. Access updated product information, browse recommendations by application, and view relevant data. Available in German, English, and Chinese.

**Highlights:** Updated product information, Additive recommendations by application, Relevant product data, Multilingual support (DE, EN, CN)

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

**In-app purchases:** none


### PSSI

[App page](https://appshunter.io/ios/app/pssi/id6499057790)

**In-app purchases:** none


## Frequently asked questions

### Is BYK Additive Guide free?

BYK Additive Guide is free to download, with no in-app purchases.

### Is PSSI free?

PSSI is free to download, with no in-app purchases.

### Do BYK Additive Guide or PSSI have ads?

Neither BYK Additive Guide nor PSSI shows ads.

### Which is updated more often, BYK Additive Guide or PSSI?

BYK Additive Guide ships an update every 4 months, and PSSI every 2 days. Most recently, BYK Additive Guide was updated on October 14, 2026 and PSSI on September 25, 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.*