# Instrument Toolbox vs PLC IO Checkout

The clearest difference is price: PLC IO Checkout at Free against Instrument Toolbox's $1.99. Instrument Toolbox's advantage is in-app purchases (none vs 1) and iOS requirement (13.0 vs 17.0). On ads and device support there is nothing between them.

PLC IO Checkout is free to download; Instrument Toolbox costs $1.99 up front. PLC IO Checkout sells 1 one-off in-app purchase. Instrument Toolbox asks for nothing beyond the download.

## The numbers

| Metric | Instrument Toolbox | PLC IO Checkout |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Weekly | — |
| Monetization | Paid | — |
| Size | 8 MB | 2 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [立娜 王](https://appshunter.io/developer/1761096632) | [BCDPRODUCTION LLC](https://appshunter.io/developer/1867250803) |

## What reviewers say

### Instrument Toolbox

[App page](https://appshunter.io/ios/app/instrument-toolbox/id6698856248)

A professional calculator designed for industrial control, automation, and instrumentation engineers. It offers quick conversions and calculations for gas concentration, units, steam properties, flange levels, and pipeline flow. Ideal for both field debugging and engineering design.

**Highlights:** PPM to mg/m³ conversion with compensation, Industrial unit conversion (pressure, volume, temp, etc.), Saturated steam pressure and density calculator, Flange level migration calculations, Pipeline flow and velocity calculator, Real-time calculation results

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

**In-app purchases:** none


### PLC IO Checkout

[App page](https://appshunter.io/ios/app/plc-io-checkout/id6810327015)

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Unlock | $29.99 | one-time |


## Frequently asked questions

### Is Instrument Toolbox free?

Instrument Toolbox costs $1.99, with no in-app purchases.

### Is PLC IO Checkout free?

PLC IO Checkout is free to download, with in-app purchases available.

### Do Instrument Toolbox or PLC IO Checkout have ads?

Neither Instrument Toolbox nor PLC IO Checkout shows ads.

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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.*