# STP One vs Cadaclysm

The clearest difference is in-app purchases: Cadaclysm at none against STP One's 2. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. STP One sells 2 in-app purchases, starting at $9.99 per month. Cadaclysm asks for nothing beyond the download.

STP One ships an update every 3 days, Cadaclysm every 4 days. The most recent releases landed on October 10, 2026 and October 22, 2026 respectively.

## The numbers

| Metric | STP One | Cadaclysm |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 4 days |
| Size | 13 MB | 12 MB |
| Requires iOS | **16.4** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [JAEYUN HWANG](https://appshunter.io/developer/6799562363) | [Blitter](https://appshunter.io/developer/6816093397) |

## What reviewers say

### STP One

[App page](https://appshunter.io/ios/app/stp-one-step-cad-viewer/id6802912144)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 스텝원 Pro 월간 | $9.99 | per month |
| 스텝원 Pro 연간 | $69.99 | per year |


### Cadaclysm

[App page](https://appshunter.io/ios/app/cadaclysm/id6816093395)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is STP One free?

STP One is free to download, with in-app purchases available.

### Is Cadaclysm free?

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

### Do STP One or Cadaclysm have ads?

Neither STP One nor Cadaclysm shows ads.

### Which is updated more often, STP One or Cadaclysm?

STP One ships an update every 3 days, and Cadaclysm every 4 days. Most recently, STP One was updated on October 10, 2026 and Cadaclysm on October 22, 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.*