# E仪表 vs Instrument Toolbox

The clearest difference is price: E仪表 at Free against Instrument Toolbox's $1.99. Instrument Toolbox's advantage is update cadence (weekly vs every 24 months) and iOS requirement (13.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

E仪表 is free to download; Instrument Toolbox costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

E仪表 ships an update every 24 months, Instrument Toolbox weekly. The most recent releases landed on September 16, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | E仪表 | Instrument Toolbox |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 24 months | **Weekly** |
| Monetization | — | Paid |
| Size | 24 MB | 8 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [律 潘](https://appshunter.io/developer/1224263383) | [立娜 王](https://appshunter.io/developer/1761096632) |

## What reviewers say

### E仪表

[App page](https://appshunter.io/ios/app/e/id1637254387)

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

**In-app purchases:** none


### 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


## Frequently asked questions

### Is E仪表 free?

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

### Is Instrument Toolbox free?

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

### Do E仪表 or Instrument Toolbox have ads?

Neither E仪表 nor Instrument Toolbox shows ads.

### Which is updated more often, E仪表 or Instrument Toolbox?

E仪表 ships an update every 24 months, and Instrument Toolbox weekly. Most recently, E仪表 was updated on September 16, 2026 and Instrument Toolbox on September 23, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*