Comparison

Simplex Nodal vs Lume Test

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

Head to head
About

Simplex Nodal

Explore electricity markets by building and solving your own models. This app visually demonstrates complex concepts like locational marginal pricing, line losses, and the simplex algorithm. Learn through interactive examples and detailed step-by-step operations.

Highlights
  • Build and solve electricity market models
  • Visualize simplex algorithm workings
  • Explore locational marginal pricing
  • Understand line losses and binding constraints
  • Step-by-step simplex iteration details
  • Export simplex tableaux as CSV
  • Includes sample market models
Read full description

In conjunction with the tutorial document, available at www.simplexnodal.com, use the app to learn about electricity markets by graphically building and solving your own electricity market models. The tutorial also describes the simplex algorithm that solves the model and the app lets you see the internal workings of the algorithm. Demonstrates nodal electricity markets features such as: locational marginal pricing, line losses, parallel flows, binding constraints, price separation, the spring washer effect, negative prices, risk and reserves, ramp-rates, congestion charges, transmission rentals, multiple electrical islands, HVDC branches, HVDC risk, HVDC risk subtractor, HVDC reserve sharing, and more. See www.simplexnodal.com for more screenshots and the tutorial document. Highlights: • The tutorial explains nodal electricity markets and the simplex algorithm via worked examples using the app • Start with small models to learn the basic concepts of the electricity market model the simplex algorithm • Learn how to explain prices by relaxing constraints to determine shadow prices • Enable/disable electricity market features to focus on individual effects, e.g., risk and reserve is easier to explain with line losses disabled • View full details of the simplex modelling including basic and non-basic variables, constraints, shadow prices, and details of the simplex iterations • Learn how the simplex algorithm works by viewing the step by step simplex operations that solve the electricity market model. View iteration details in the app and/or export the simplex tableaux as a csv file • The app implements its own simplex algorithm but you can also export the model in GAMS format to solve externally if you have access to the GAMS solver • Includes sample models that represent sections of an actual electricity market iPhone and iPad functionality is the same. Zoom and scroll allow the iPhone to access iPad sized models.

About

Lume Test

Prepare for English proficiency tests like PTE Academic, TOEIC, and IELTS with AI-powered feedback on speaking and writing. Track your progress with detailed analytics and personalized study plans to accelerate your learning.

Highlights
  • AI-powered speaking assessment
  • Professional essay marking
  • Grammar and spelling correction
  • Reading and listening practice tests
  • Scored practice tests
  • Detailed performance analytics
  • Custom study planner
Features
Read full description

Ready to ace your PTE Academic, PTE Core, TOEIC, Duolingo English Test (DET), or IELTS Academic exam? Lume Test App transforms your preparation with AI-powered tools that motivate daily practice and accelerate your progress. Get real-time feedback and expert support at every step of your language test journey. Key Features You’ll Love: • AI-Powered Speaking Assessment - Receive instant, detailed feedback on pronunciation, fluency, and content with our advanced speech recognition technology • Professional Essay Marking - Perfect your writing with comprehensive feedback aligned with official exam criteria • Grammar and Spelling Check: Write flawlessly as AI catches and corrects grammar and spelling mistakes instantly. • Reading Practice: Strengthen your comprehension with practice tests and detailed answers that help you master key points. • Listening Practice: Simulate the real exam with mock tests that build your listening skills and exam-day confidence. • Scored Practice Tests: Practice like the real exam with our vast question bank and a test interface that mirrors the actual format. • Detailed Performance Analytics - Track progress with comprehensive score breakdowns and personalized insights • Custom Study Planner - Stay motivated with adaptive weekly and monthly goals tailored to your learning pace WHY CHOOSE LUME? LUME isn’t just another prep app—it’s your personal coach, combining AI-driven insights with expert-designed content to boost your confidence and sharpen your skills. Whether it’s speaking, writing, or test strategy, LUME is built to guide you to success. GET STARTED NOW Ready to light up your test prep journey? Visit www.lumetest.com to learn more or download the app and start practicing today! GET IN TOUCH Have feedback, questions, or suggestions? We’d love to hear from you! Reach out to us at support@lumetest.com

Screenshots

Simplex Nodal4 screens
Lume Test4 screens

Verdict

The call

The clearest difference is in-app purchases: Simplex Nodal at none against Lume Test's 8. Simplex Nodal also leads on iOS requirement (9.0 vs 15.1). Lume Test's advantage is update cadence (every 2 weeks vs every 4 months). On price, review sentiment, ads and device support 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. Lume Test sells 8 one-off in-app purchases. Simplex Nodal asks for nothing beyond the download.

UpkeepUpdate frequency

Simplex Nodal ships an update every 4 months, Lume Test every 2 weeks. The most recent releases landed on November 1, 2026 and October 30, 2026 respectively.

Scorecard4 real differences · 6 level
Simplex Nodal versus Lume Test: the parameters behind the verdict, then further details
ParameterSimplex NodalLume Test
PriceFreeFree
Rating—5.0 (1 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings—1 — better
Update frequencyEvery 4 monthsEvery 2 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod, Mac — betteriPhone, iPad, iPod
Requires iOS9.0 — better15.1
Further details — not scored
Size14 MB115 MB
Age rating4+4+
DeveloperSimplex Nodal LimitedLUME EDUCATION GROUP PTY LTD

Customer experience

Simplex Nodal

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Lume Test

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Simplex Nodal

No in-app purchases

8 purchases

Lume Test

One-time8
  • PTE Academic: 30 Days$19.00
  • PTE Core: 30 Days$19.00
  • PTE Academic: 60 Days$29.00
Show 5 more
  • PTE Core: 60 Days$29.00
  • PTE Academic: 90 Days$39.00
  • PTE Core: 30 Days$39.00
  • PTE Academic: 180 Days$69.00
  • PTE Core: 180 Days$69.00

Questions

Is Simplex Nodal free?
Simplex Nodal is free to download, with no in-app purchases.
Is Lume Test free?
Lume Test is free to download, with in-app purchases available.
Do Simplex Nodal or Lume Test have ads?
Neither Simplex Nodal nor Lume Test shows ads.
Which is updated more often, Simplex Nodal or Lume Test?
Simplex Nodal ships an update every 4 months, and Lume Test every 2 weeks. Most recently, Simplex Nodal was updated on November 1, 2026 and Lume Test on October 30, 2026.

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