# Control System Calc vs OT Toolbox

The clearest difference is ads: OT Toolbox at none against Control System Calc's shown. OT Toolbox also leads on update cadence (weekly vs fortnightly). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Control System Calc sells 1 one-off in-app purchase and OT Toolbox sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Control System Calc ships an update fortnightly, OT Toolbox weekly. Both last shipped on November 10, 2026.

## The numbers

| Metric | Control System Calc | OT Toolbox |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Fortnightly | **Weekly** |
| Size | 10 MB | 10 MB |
| Requires iOS | **17.0** | 18.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [洋 刘](https://appshunter.io/developer/6775317751) | [Dominik Gausmann](https://appshunter.io/developer/1870320985) |

## What reviewers say

### Control System Calc

[App page](https://appshunter.io/ios/app/control-system-calc/id6791956580)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Control System Calc Pro | $3.99 | one-time |


### OT Toolbox

[App page](https://appshunter.io/ios/app/ot-toolbox-plc-and-automation/id6815303257)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OT Toolbox Pro | $3.99 | one-time |


## Frequently asked questions

### Is Control System Calc free?

Control System Calc is free to download, with in-app purchases available.

### Is OT Toolbox free?

OT Toolbox is free to download, with in-app purchases available.

### Do Control System Calc or OT Toolbox have ads?

Control System Calc shows ads; OT Toolbox does not.

### Which is updated more often, Control System Calc or OT Toolbox?

Control System Calc ships an update fortnightly, and OT Toolbox weekly. Most recently, Control System Calc was updated on November 10, 2026 and OT Toolbox on November 10, 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.*