# Lambert vs ResToolbox3

The clearest difference is update cadence: ResToolbox3 at every 6 days against Lambert's every 5 months. On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Lambert against 5.0 for ResToolbox3. Both are backed by a comparable volume of ratings — 4 and 2 respectively.

Lambert ships an update every 5 months, ResToolbox3 every 6 days. The most recent releases landed on October 3, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Lambert | ResToolbox3 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (4 ratings)](https://appshunter.io/ios/app/lambert/id341216494/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/restoolbox3/id6759464322/reviews) |
| Number of ratings | **4** | 2 |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 6 days** |
| Monetization | Free | Free |
| Size | 3 MB | 25 MB |
| Requires iOS | 16.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Peter Appel](https://appshunter.io/developer/341216497) | [MobileReservoir](https://appshunter.io/developer/497057811) |

## What reviewers say

### Lambert

[App page](https://appshunter.io/ios/app/lambert/id341216494)

This application transforms your iPhone into a specialized geological compass. It accurately measures the dip direction and angle of geological strata, displaying real-time orientation data. Measurements can be enhanced with text and plotted on a map for easy transfer to your computer.

**Highlights:** Geological compass functionality, Measure dip direction and angle, Real-time stereographic projection, Wulff and Schmidt Net projection diagrams, Add text to measurements, Plot measurement localities on a map, Transfer data to computer

**Features:** macOS Compatibility

**In-app purchases:** none


### ResToolbox3

[App page](https://appshunter.io/ios/app/restoolbox3/id6759464322)

This petroleum engineering calculator provides rapid answers for engineers in the field or office. It offers comprehensive tools for fluid properties, gas hydrate prediction, nodal analysis, production forecasting, volumetrics, and well testing, all accessible offline.

**Highlights:** Fluid properties (PVT) analysis, Gas hydrate prediction, Nodal analysis for wells, Production forecasting, Volumetric calculations, Well test analysis, Offline functionality

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

**In-app purchases:** none


## Frequently asked questions

### Is Lambert free?

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

### Is ResToolbox3 free?

ResToolbox3 is free to download, with no in-app purchases.

### Which has better reviews, Lambert or ResToolbox3?

Lambert and ResToolbox3 are both rated 5.0 out of 5 on the App Store, from 4 and 2 ratings respectively.

### Do Lambert or ResToolbox3 have ads?

Neither Lambert nor ResToolbox3 shows ads.

### Which is updated more often, Lambert or ResToolbox3?

Lambert ships an update every 5 months, and ResToolbox3 every 6 days. Most recently, Lambert was updated on October 3, 2026 and ResToolbox3 on October 8, 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.*