# Drilling Engineering vs TallyRig

The clearest difference is in-app purchases: Drilling Engineering at none against TallyRig's 1. Drilling Engineering also leads on iOS requirement (7.0 vs 15.0). TallyRig's advantage is update cadence (every 3 months vs every 42 months). On price, ads and device support there is nothing between them.

Both are free to download. TallyRig sells 1 one-off in-app purchase. Drilling Engineering asks for nothing beyond the download.

Drilling Engineering ships an update every 42 months, TallyRig every 3 months. The most recent releases landed on October 24, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Drilling Engineering | TallyRig |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.8 (19 ratings)](https://appshunter.io/ios/app/drilling-engineering/id891302915/reviews)** | — |
| Number of ratings | **19** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 42 months | **Every 3 months** |
| Monetization | Free | — |
| Size | 8 MB | 33 MB |
| Requires iOS | **7.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [PT. Pertamina (Persero)](https://appshunter.io/developer/541838859) | [嘉炜 丰](https://appshunter.io/developer/1759511819) |

## What reviewers say

### Drilling Engineering

[App page](https://appshunter.io/ios/app/drilling-engineering/id891302915)

This app provides essential tools for oil and gas professionals involved in drilling operations. It offers unit conversions, a comprehensive drilling calculator, API tubular data, stuck pipe problem identification, and well control calculations.

**Highlights:** Petroleum Unit Conversion, Drilling Calculator (90+ calculations), API Tubular Data, Stuck Pipe Problem Identification, Well Control Kill Sheet

**Features:** macOS Compatibility

**In-app purchases:** none


### TallyRig

[App page](https://appshunter.io/ios/app/tallyrig-well-control-calc/id6758645641)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| TallyRig Pro | $14.99 | one-time |


## Frequently asked questions

### Is Drilling Engineering free?

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

### Is TallyRig free?

TallyRig is free to download, with in-app purchases available.

### Do Drilling Engineering or TallyRig have ads?

Neither Drilling Engineering nor TallyRig shows ads.

### Which is updated more often, Drilling Engineering or TallyRig?

Drilling Engineering ships an update every 42 months, and TallyRig every 3 months. Most recently, Drilling Engineering was updated on October 24, 2026 and TallyRig on October 6, 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.*