Comparison

Rockd vs Petroleum Engineering+

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Rockd

Discover and document the geology around you. Access global geologic maps, 3D globes, and detailed summaries of your surroundings. Contribute your own observations and track your exploration of Earth's geologic history.

Highlights
  • Interactive global geologic maps
  • 3D virtual globe exploration
  • Field observation logging
  • Offline map caching
  • Paleogeographic map access
  • Stratigraphic column viewing
  • Geologic literature integration
Features
Read full description

Explore, learn about, and document your geologic surroundings! Whether you are a professional geoscientist or curious about the rocks around you and the stories they tell, Rockd allows you to explore and learn about the geologic record, contribute your own observations, and log your journey through the geologic record. Features: - Instant access to geologic and geographic summaries of your current location via a Dashboard - Interactive global access to more than 290 geologic maps, with more being added weekly - Explore the landscape with a dynamic, 3D virtual globe - Save maps for use in the field with a built-in map caching system - See your past location and explore paleogeographic maps from C.R. Scotese and GPlates - View Macrostrat stratigraphic columns where available (beta) - Explore published literature containing mentions of mapped geologic units (when available) via xDD (formerly, GeoDeepDive) - Elevation data for most points on Earth from digital elevation models (DEMs) - Add your own field observations even offline; tag features from Macrostrat and the Paleobiology Database - Record strike/dip or trend/plunge for geologic features, using your phone's compass - Track your progress through the geologic record privately, or share it with others - See the public activity of other users and share your own and other public checkins using unique URLs Rockd is produced by the Macrostrat lab in the Department of Geoscience at the University of Wisconsin - Madison. Support provided by the National Science Foundation (NSF) and the Dept. of Geoscience. Experiencing issues? Send an email to contact@rockd.org and we will do our best to help you resolve it.

About

Petroleum Engineering+

Master petroleum engineering concepts through engaging quizzes covering a wide range of topics from geology to production. Ideal for students and professionals seeking to enhance their knowledge and skills in the oil and gas industry.

Highlights
  • Comprehensive quiz coverage
  • Topics from geology to production
  • Boost knowledge and skills
  • Engaging learning experience
  • Suitable for students and professionals
Features
Read full description

Master Petroleum Engineering with Fun and Engaging Quizzes! Dive into the world of Petroleum Engineering with our comprehensive quiz app, designed to boost your knowledge, confidence, and skills. Whether you're a student, practitioner, or just exploring the field, this app is your ultimate companion for learning and growth. Topics Covered: Introduction to Petroleum Engineering: -History and evolution of the petroleum industry", -Overview of upstream, midstream, and downstream sectors -Role of petroleum engineers Petroleum Geology and Geophysics: - Origin and accumulation of hydrocarbons - Types of reservoir rocks and cap rocks - Structural and stratigraphic traps - Seismic methods and interpretation - Geological mapping and subsurface modeling Drilling Engineering: - Types of drilling rigs and their components - Drilling fluids and their properties - Casing design and cementing practices - Directional and horizontal drilling - Drill string design and bit selection Reservoir Engineering Fundamentals: - Reservoir fluid properties (PVT analysis) - Porosity and permeability measurement - Fluid saturation and capillary pressure - Material balance and reservoir drive mechanisms - Reservoir characterization and classification Well Logging and Formation Evaluation: - Types of logging tools (SP, gamma ray, resistivity) - Nuclear and acoustic logging techniques - Interpretation of log data for reservoir evaluation - Core sampling and laboratory analysis - Formation testing and pressure transient analysis Production Engineering: - Well completion techniques (open hole, cased hole) - Artificial lift systems (ESP, gas lift, rod pumps) - Well stimulation (acidizing, hydraulic fracturing) - Flow assurance and sand control - Production monitoring and optimization Enhanced Oil Recovery (EOR) Techniques: - Primary, secondary, and tertiary recovery concepts - Thermal methods (steam flooding, in-situ combustion) - Gas injection (CO₂, nitrogen, miscible flooding) - Chemical EOR (polymer, surfactant, alkaline) - Screening criteria and field implementation Natural Gas Engineering: - Gas properties and phase behavior - Gas reservoir performance and deliverability - Gas production and compression systems - Gas processing and dehydration - Liquefied natural gas (LNG) and gas monetization Petroleum Refining and Processing: - Overview of refining processes - Atmospheric and vacuum distillation - Conversion processes (cracking, reforming) - Product blending and specifications - Emission control and waste management Surface Facilities and Field Processing: - Field processing of oil, gas, and water - Separation equipment and design - Flowlines, pipelines, and gathering systems - Surface facility layout and operation - Maintenance and integrity management Reservoir Simulation and Modeling: Formation Damage and Wellbore Integrity: Health, Safety, and Environmental Management (HSE): Petroleum Economics and Project Evaluation: Features You'll Love: - Adaptive Quizzes: Questions tailored to your skill level, ensuring a personalized learning experience. - Detailed Explanations: Learn as you go with in-depth answers and references. - Timed Challenges: Test your speed and accuracy under time pressure for an extra thrill. - Progress Tracking: Keep tabs on your improvement with detailed analytics and reports. - User-Friendly Design: Intuitive interface for smooth navigation and focus. Who is it for? - Petroleum Engineering students preparing for exams. - Professionals brushing up on their knowledge. - Anyone interested in understanding the principles of occupational therapy. Download now and make learning occupational therapy enjoyable and effective! Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://forwaelade.web.app/PetroleumEngineering/privacy-policy

Screenshots

Rockd4 screens
Petroleum Engineering+4 screens

Verdict

The call

The clearest difference is rating: Petroleum Engineering+ at 5.0 against Rockd's 4.4. Petroleum Engineering+ also leads on update cadence (monthly vs every 3 months). Rockd's advantage is in-app purchases (none vs 6) and ratings volume (185 vs 1). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Petroleum Engineering+ sells 6 in-app purchases, starting at $9.99 per month. Rockd asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Petroleum Engineering+ holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: Rockd has 185 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

Rockd ships an update every 3 months, Petroleum Engineering+ monthly. The most recent releases landed on September 18, 2026 and September 23, 2026 respectively.

Scorecard5 real differences · 5 level
Rockd versus Petroleum Engineering+: the parameters behind the verdict, then further details
ParameterRockdPetroleum Engineering+
PriceFreeFree
Rating4.4 (185 ratings)5.0 (1 ratings) — better
Positive reviews73.3% of reviews—
Number of ratings185 — better1
Update frequencyEvery 3 monthsMonthly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.6 — better17.0
Further details — not scored
Size259 MB18 MB
Age rating4+4+
DeveloperUniversity of Wisconsin-Madison Shared AppsForwa Elade Wunde

Customer experience

Rockd

All ratings185 ratings
Positive82.2%
Neutral7.6%
Negative10.3%
Written reviews90 reviews
Positive73.3%
Neutral13.3%
Negative13.3%

Petroleum Engineering+

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Rockd

Reported bugs

17 issues
  • Black map display in airplane mode and online
  • Persistent error dialogs that cannot be dismissed
  • GPS not tracking in real-time
  • Offline check-ins not syncing properly
  • Sign-up page jumps between fields and login page
Show 12 more
  • Fossils button not working
  • Map returns to user location after viewing check-ins
  • App crashes and becomes unresponsive
  • Data loss after app reinstall or logout
  • Maps fail to load after recent updates
  • Location search functionality broken
  • Android version windows not visible
  • Straight lines appear when zooming
  • Formations stop at state lines
  • Check-in screen stuck with no exit option
  • App won't load after initial use
  • Geological overlay won't upload to base map

Requested features

16 requests
  • Follow/friend mechanic to track other users' check-ins
  • Rock identification tool from photo uploads
  • Offline map download with customizable zoom levels
  • Stereonet tool for structural geology
  • Groundwater/aquifer information section
Show 11 more
  • Map legend/key for geological features
  • Spanish language support
  • Ability to move dashboard to different locations
  • Latitude/longitude search functionality
  • Multiple photo attachments per location
  • Strike and dip data visualization
  • Fault line labeling on maps
  • Better Android version compatibility
  • Tutorial or short course for advanced features
  • Black contact lines between formations toggle
  • Personal photo upload focus with mineral variations

Petroleum Engineering+

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Rockd

No in-app purchases

6 purchases

Petroleum Engineering+

Subscriptions3
  • 1 Month$9.991 Month
  • 6 Months$19.996 Months
  • 1 Year$29.991 Year
One-time3
  • 1500$0.99
  • 3500$1.99
  • 9000$3.99

Questions

Is Rockd free?
Rockd is free to download, with no in-app purchases.
Is Petroleum Engineering+ free?
Petroleum Engineering+ is free to download, with in-app purchases available.
Which has better reviews, Rockd or Petroleum Engineering+?
Petroleum Engineering+ is rated higher. Rockd averages 4.4 out of 5 from 185 ratings, while Petroleum Engineering+ averages 5.0 from 1 ratings.
Do Rockd or Petroleum Engineering+ have ads?
Neither Rockd nor Petroleum Engineering+ shows ads.
Which is updated more often, Rockd or Petroleum Engineering+?
Rockd ships an update every 3 months, and Petroleum Engineering+ monthly. Most recently, Rockd was updated on September 18, 2026 and Petroleum Engineering+ on September 23, 2026.

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