# Instrument Toolbox vs 视力启蒙

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

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

## The numbers

| Metric | Instrument Toolbox | 视力启蒙 |
| --- | --- | --- |
| 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 | 25 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [立娜 王](https://appshunter.io/developer/1761096632) | [敬 潘](https://appshunter.io/developer/1630712468) |

## 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


### 视力启蒙

[App page](https://appshunter.io/ios/app/id6737162932)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Professional | $2.99 | one-time |


## Frequently asked questions

### Is Instrument Toolbox free?

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

### Is 视力启蒙 free?

视力启蒙 is free to download, with in-app purchases available.

### Do Instrument Toolbox or 视力启蒙 have ads?

Neither Instrument Toolbox nor 视力启蒙 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.*