# Dr. DE

> Drilling engineering calculation toolbox for engineers and technicians. (iPhone/iPad app by Pegasus Vertex, Inc..)

- Source: https://appshunter.io/ios/app/dr-de/id954796004 (this page in markdown: same URL + `.md`)
- Developer: [Pegasus Vertex, Inc.](https://appshunter.io/developer/954796003)
- Category: Utilities
- Price: Free
- Rating: 4.50/5 from 16 App Store ratings · 9 written reviews indexed
- Age rating: 17+
- Requires: iOS 15.6 · 33 MB
- Languages: American English
- Released: 2015-01-11
- Data updated: 2026-07-18
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/dr-de/id954796004/reviews.md

## What is Dr. DE?

Do you want to solve drilling engineering problems in seconds? It is easier than ever before to use Dr. DE Lite mobile app, a must-have toolbox app that includes a substantial collection of functions for every drilling engineer and technician.

Bid farewell to flipping through handbooks, textbooks, standards, etc. for answers. This free app, sophisticated yet simple to use, not only saves time and money, but also makes your engineering and sales efforts more reliable and professional.

The Dr. DE Lite app is equipped with 29 functions that are divided into 11 groups.

--Bit Hydraulics
--Casing Centralizer
--Hole Cleaning
--Hydraulics
--Mud Additives
--Pipe
--Pump
--Tank Capacity
--Volume and Capacity
--Well Control
--Unit Conversion

## Key features

- 29 drilling engineering functions
- 11 functional groups
- Bit hydraulics calculations
- Hole cleaning analysis
- Well control solutions
- Unit conversion tools
- Tank capacity calculations

## Recent user reviews (9 of 9)

All indexed reviews: https://appshunter.io/ios/app/dr-de/id954796004/reviews.md

### 1/5 — Useless

*2025-06-05, version 3.1.0*

This use to be the best when it was an offline calculator, now it needs a data connection to load.. unfortunately we work in the oilfield and usually don’t have one in the working area

### 1/5 — Good when it works.

*2024-12-29, version 3.1.0*

Used this app for a while. It was great. Last updates to IOS, it won’t even load. It’s useless.

### 1/5 — Was a very nice app

*2024-11-26*

Used this app for a while. It was great. Last updates to IOS, it won’t even load. It’s useless.

### 4/5 — Dr.De

*2024-02-15, version 3.0.1*

Hi
This app don’t open for my iPhone 
Please check

### 5/5 — Great for field work!

*2019-06-21, version 1.0.4*

If you’re on the my pits and you need a quick mud mix calc, this app is amazing. That’s the main feature I use, being a mud engineer. And it’s usually right on the money within 1/10 of a ppg.

### 1/5 — Keeps Kicking Me Out

*2018-06-21, version 1.0.2*

When trying to use app it keeps kicking me out of app and back to the home screen.

### 5/5 — Best

*2017-08-04, version 1.0.2*

Excellent excellent excellent

### 5/5 — Drilling engineer

*2015-02-06, version 1.0.1*

A simple-to-use and easy-to-learn app for a busy drilling engineer like me. 

A good start!

### 5/5 — Professional, accurate, east to use

*2015-01-12, version 1.0.0*

It's the best drilling toolbox app I've ever used. Quick calculate, accurate results, search function and more.

## Frequently asked questions about Dr. DE

### What is Dr. DE used for?

Dr. DE is a mobile toolbox designed to solve drilling engineering problems quickly. It offers 29 functions across 11 categories, helping engineers and technicians with calculations related to hydraulics, hole cleaning, well control, and more.

### How many functions does Dr. DE have?

Dr. DE is equipped with a substantial collection of 29 functions, divided into 11 distinct groups to cover various aspects of drilling engineering.

### Is Dr. DE free to use?

Yes, Dr. DE is a free app. It does not require any payment to download or use its features.

### What devices does Dr. DE support?

Dr. DE is available on iPhone, iPad, and iPod devices, making it accessible for mobile users in the field.

### How often is Dr. DE updated?

The latest version of Dr. DE is 3.2.1, which was last updated on November 26, 2025. This indicates a commitment to ongoing development and improvements.

### What is the age rating for Dr. DE?

Dr. DE has an age rating of 17+, suggesting it contains content or complexity suitable for mature users in the engineering field.

### Does Dr. DE have ads?

No, Dr. DE does not contain advertisements. Users can utilize its engineering tools without interruption.

### What is the user rating for Dr. DE?

Dr. DE has received positive feedback, with an average rating of 4.5 stars from 16 ratings.

## Version history (last 5 releases)

### 3.2.1 — 2025-11-26

Fixed issue.

### 3.2.0 — 2025-11-06

What is new:
Add more functions under Centralizer, Hydraulics and Mud Group
● Casing Centralizer: Casing Sag
● Casing Centralizer: Standoff of Rigid Centralizer
● Hydraulics: Surge & Swab
● Hydraulics: Flow Split
● Hydraulics: Critical Static Gel Strength
● Hydraulics: Annular Shear Rate
● Mud Additives: Brine Density Change

### 3.1.0 — 2024-04-16

1. Fix issue.
2. Update share feature.
3. Adding the new function.

### 3.0.1 — 2024-01-29

Fixed issue.

### 3.0.0 — 2024-01-16

1) UI and interaction redesign
2) Adding the feedback and language feature.
3) Fixed issue.

## Apps similar to Dr. DE

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [McWane Pocket Engineer v2](https://appshunter.io/ios/app/mcwane-pocket-engineer-v2/id882265820) | 3.9 (10) | Free | Utilities |
| [HVAC Pipe Sizer Plus](https://appshunter.io/ios/app/hvac-pipe-sizer-plus/id352069594) | 3.0 (1) | $13.99 | Utilities |
| [FracAppz App](https://appshunter.io/ios/app/fracappz-app/id959223557) | 5.0 (4) | Free | Utilities |
| [HVAC Duct Sizer](https://appshunter.io/ios/app/hvac-duct-sizer/id317970395) | 2.9 (8) | $5.99 | Utilities |
| [TracPipe CounterStrike Guide](https://appshunter.io/ios/app/tracpipe-counterstrike-guide/id996885333) | 3.4 (7) | Free | Utilities |
| [Keystone Pump TDH Calculator](https://appshunter.io/ios/app/keystone-pump-tdh-calculator/id880925443) | 5.0 (1) | Free | Utilities |

## More apps by Pegasus Vertex, Inc.

- [CEMPRO Lite](https://appshunter.io/ios/app/cempro-lite/id1116681742)
- [CentraDesign Lite](https://appshunter.io/ios/app/centradesign-lite/id1157895841)
- [CleanMax Lite](https://appshunter.io/ios/app/cleanmax-lite/id1190494072)
- [MUDSheet](https://appshunter.io/ios/app/mudsheet/id1510513381)

All apps by Pegasus Vertex, Inc.: https://appshunter.io/developer/954796003

## Related topics

[drilling engineering](https://appshunter.io/ios/topics/drilling-engineering) · [well control](https://appshunter.io/ios/topics/well-control) · [de vossenberg](https://appshunter.io/ios/topics/de-vossenberg) · [drilling](https://appshunter.io/ios/topics/drilling)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-18.*