Comparison

Part66 vs Mechanical Formula

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

Head to head
About

Part66

Prepare for EASA Part 66 aircraft maintenance license exams with sample tests and flashcards. Generate unlimited random exams and analyze results to identify weak areas. Covers modules relevant to B1.1 and potentially FAA licenses.

Highlights
  • Sample exams for EASA Part 66 modules
  • Flashcards for purchased modules
  • Unlimited random exam generation
  • Exam timer with real-world time limits
  • Analysis of results and weak point identification
  • Email results for review
Features
Read full description

Part66-Engineer app is for prospective aircraft engineers who are studying for their EASA Part 66 basic maintenance licence; the app offers a full range of sample exams from Module 1 to Module 17 specifically tailored to meet the B1.1 licence. As of Version 3.0(24/11/2018); Module 7, Module 8, Module 9, Module 10, Module 15 and Module 17 have exams and flashcards available for purchase. Flashcards are now added for all the completed modules (7,8,9,10,15 & 17). Many questions are also similar to the FAR Part-65 standard for those engineers applying for their FAA license. Exams will be available for all modules in upcoming releases. Version 3.0 includes the option to download a question and flashcard bank and the user can generate unlimited random exams from the available questions. Each exam is set to the same standard as a 'real' EASA Part-147 supplied exam. Exam timer shows the real world time available for each exam and no questions are repeated. The user is able to email and analyze their results. The app will highlight weak points and give a suggested reading. Total questions available in this app = 5,472 questions. Total questions available per Module for this version: Module 1 = 32 Module 2 = 52 Module 3 = 52 Module 4 = 20 Module 5 = 50 Module 6 = 72 Module 7 = 844 questions & 780 flashcards. Module 8 = 239 questions & 170 flashcards. Module 9 = 290 questions & 242 flashcards. Module 10 = 426 questions & 304 flashcards. Module 11 = 140 Module 15 = 665 questions & 480 flashcards. Module 17 = 443 questions & 171 flashcards.

About

Mechanical Formula

This app provides over 200 essential mechanical engineering formulas and calculations in a user-friendly tool. It's designed to simplify complex concepts and speed up problem-solving for students, professionals, and educators.

Highlights
  • 200+ mechanical engineering formulas
  • Instant calculations
  • Intuitive interface
  • Real-world application explanations
  • Exam preparation aid
  • Lifetime Premium option
Features
Read full description

The Mechanical Engineering Formula & Calculator app brings together 200+ essential mechanical engineering formulas and calculations in one powerful and easy-to-use tool. Designed specifically for mechanical students, professionals, and educators, this app simplifies complex concepts and makes problem-solving faster and more accurate. Developed by engineers for engineers, this app covers a wide range of mechanical engineering topics, helping users understand the principles behind each formula and how they are applied in real-world scenarios. Whether you are studying, revising, or working on-site, this app serves as your reliable engineering companion. With an intuitive interface, you can easily select any calculator, enter the required values, and get instant results with clear output. No complicated steps — just accurate calculations at your fingertips. Perfect for: - Mechanical engineering students - Practicing engineers - Technical instructors - Exam preparation & quick reference Boost your productivity and master mechanical calculations with confidence. In app purchase included : Lifetime Premium Privacy policy : https://chatlyst.in/privacy.html Terms and condition : https://chatlyst.in/tcondition.html

Screenshots

Part664 screens
Mechanical Formula4 screens

Verdict

The call

The clearest difference is review sentiment: Part66 at 60% against Mechanical Formula's 0%. Part66 also leads on update cadence (every 2 months vs every 4 months) and iOS requirement (10.3 vs 13.0). Mechanical Formula's advantage is rating (4.7 vs 4.5) and ratings volume (34 vs 10). On price, ads, in-app purchases and monetization model 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. Part66 sells 11 one-off in-app purchases and Mechanical Formula sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Mechanical Formula holds the better App Store score, 4.7 against 4.5. Both are backed by a comparable volume of ratings — 10 and 34 respectively. Written reviews complicate that: 60% of Part66's written reviews are positive against 0% of Mechanical Formula's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Part66 ships an update every 2 months, Mechanical Formula every 4 months. The most recent releases landed on September 30, 2026 and October 6, 2026 respectively.

Scorecard5 real differences · 5 level
Part66 versus Mechanical Formula: the parameters behind the verdict, then further details
ParameterPart66Mechanical Formula
PriceFreeFree
Rating4.5 (10 ratings)4.7 (34 ratings) — better
Positive reviews60.0% of reviews — better0.0% of reviews
Number of ratings1034 — better
Update frequencyEvery 2 months — betterEvery 4 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10.3 — better13.0
Further details — not scored
Size38 MB42 MB
Age rating4+4+
DeveloperDAVID SOUTHERNKantaben Gorasiya

Customer experience

Part66

All ratings10 ratings
Positive90.0%
Neutral0.0%
Negative10.0%
Written reviews5 reviews
Positive60.0%
Neutral20.0%
Negative20.0%

Mechanical Formula

All ratings34 ratings
Positive91.2%
Neutral2.9%
Negative5.9%
Written reviews1 reviews
Positive0.0%
Neutral100.0%
Negative0.0%

In-app purchases

11 purchases

Part66

One-time11
  • Module 10 Exam 2$0.99
  • module 10 Exam 3$0.99
  • Module 15 Exam 2$0.99
Show 8 more
  • Module 7 Exam 2$0.99
  • Module 8 Exam 2$0.99
  • Module 8 Exam 3$0.99
  • Module 8 Bank = 409 Questions.$7.99
  • Module 17 Full Bank = 614 Q$8.99
  • Module 10 Bank. 730 Questions.$10.99
  • Module 15 Full Bank = 1,129 Q$11.99
  • Module 7 Bank = 1,624 Question$11.99
1 purchases

Mechanical Formula

One-time1
  • Lifetime$9.99

Questions

Is Part66 free?
Part66 is free to download, with in-app purchases available.
Is Mechanical Formula free?
Mechanical Formula is free to download, with in-app purchases available.
Which has better reviews, Part66 or Mechanical Formula?
Mechanical Formula is rated higher. Part66 averages 4.5 out of 5 from 10 ratings, while Mechanical Formula averages 4.7 from 34 ratings.
Do Part66 or Mechanical Formula have ads?
Neither Part66 nor Mechanical Formula shows ads.
Which is updated more often, Part66 or Mechanical Formula?
Part66 ships an update every 2 months, and Mechanical Formula every 4 months. Most recently, Part66 was updated on September 30, 2026 and Mechanical Formula on October 6, 2026.

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