# LTH Discover vs Instrument Toolbox

The clearest difference is price: LTH Discover at Free against Instrument Toolbox's $1.99. Instrument Toolbox's advantage is update cadence (weekly vs every 5 months) and iOS requirement (13.0 vs 15.6). On ads, in-app purchases and device support there is nothing between them.

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

LTH Discover ships an update every 5 months, Instrument Toolbox weekly. The most recent releases landed on October 25, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | LTH Discover | Instrument Toolbox |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Weekly** |
| Monetization | — | Paid |
| Size | 40 MB | 8 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [L.T.H. Electronics Limited](https://appshunter.io/developer/1707298349) | [立娜 王](https://appshunter.io/developer/1761096632) |

## What reviewers say

### LTH Discover

[App page](https://appshunter.io/ios/app/lth-discover/id6476649403)

**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 LTH Discover free?

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

### Is Instrument Toolbox free?

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

### Do LTH Discover or Instrument Toolbox have ads?

Neither LTH Discover nor Instrument Toolbox shows ads.

### Which is updated more often, LTH Discover or Instrument Toolbox?

LTH Discover ships an update every 5 months, and Instrument Toolbox weekly. Most recently, LTH Discover was updated on October 25, 2026 and Instrument Toolbox on October 9, 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.*