Comparison

PrepFE vs Thermo Jesus

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

Head to head
About

PrepFE

Prepare for the FE Mechanical exam with practice problems and flashcards. Learn by doing with expert-curated content, track your progress, and identify areas for improvement. Study conveniently on your mobile device, anytime, anywhere.

Highlights
  • Practice FE exam questions
  • Interactive practice exams
  • Hundreds of practice questions
  • Detailed step-by-step explanations
  • Reinforce learning with flashcards
  • Breakdown of strengths and weaknesses
Features
Read full description

Don't spend time relearning topics from scratch and using poor resources. Jump right into practice problems and learn by doing! Supplement your learning with flash cards to learn the FE Reference Handbook and be familiar with your discipline's concepts. Take your exam practice on the go and learn with our curated content by engineering experts. Study whenever and wherever it’s convenient with PrepFE™. No need to carry around books and study guides. All you need is your phone and determination. Start your Professional Engineer journey and download the PrepFE - Mechanical app. Install the free version today and jump start your studying! We have provided a limited free version of the app that you can try before deciding to upgrade. This version includes a limited set of practice questions, flash cards, and basic progress metrics. *Practice FE exam questions* *Interactive Practice Exams* *Hundreds of Practice Questions* *Detailed & Step-by-Step Explanations* *Reinforce learning with Flash Cards* *Breakdown of strengths and weaknesses* *Updated for 2020* We have up to date content for the new category specifications: • Mathematics • Probability and Statistics • Ethics and Professional Practice • Engineering Economics • Electricity and Magnetism • Statics • Dynamics, Kinematics, and Vibrations • Mechanics of Materials • Material Properties and Processing • Fluid Mechanics • Thermodynamics • Heat Transfer • Measurements, Instrumentation, and Controls • Mechanical Design and Analysis

About

Thermo Jesus

This app provides comprehensive summaries, practice quizzes, and detailed problem solutions for thermodynamics topics. It includes a water properties calculator and an indexed equation search for easy reference. Access pre-thermo and energy topics immediately.

Highlights
  • 45+ topic summaries
  • 300+ practice quiz questions
  • 40+ practice problems/solutions
  • Water properties calculator
  • Searchable thermodynamic equations
  • Immediate access to pre-thermo and energy topics
Features
Read full description

A full access purchase gets you 45+ thermodynamic topic summaries, 300+ practice quiz questions, and 40+ practice problems/solutions. It also includes the water properties calculator! Additionally, every thermodynamic equation is indexed and searchable. The many quiz questions in the palm of your hand are a great tool to review any chapter before an exam! Access to the Pre-thermo and Energy topics available immediately.

Screenshots

PrepFE4 screens
Thermo Jesus3 screens

Verdict

The call

The clearest difference is review sentiment: Thermo Jesus at 100% against PrepFE's 17%. Thermo Jesus also leads on rating (4.0 vs 2.0) and update cadence (every 3 weeks vs every 2 months). PrepFE's advantage is ratings volume (58 vs 4). 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. PrepFE sells 6 one-off in-app purchases and Thermo Jesus sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Thermo Jesus holds the better App Store score, 4.0 against 2.0. That said, the two scores are not equally well evidenced: PrepFE has 58 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 17% of PrepFE's written reviews are positive against 100% of Thermo Jesus's.

UpkeepUpdate frequency

PrepFE ships an update every 2 months, Thermo Jesus every 3 weeks. Both last shipped on October 24, 2026.

Scorecard4 real differences · 6 level
PrepFE versus Thermo Jesus: the parameters behind the verdict, then further details
ParameterPrepFEThermo Jesus
PriceFreeFree
Rating2.0 (58 ratings)4.0 (4 ratings) — better
Positive reviews16.7% of reviews100.0% of reviews — better
Number of ratings58 — better4
Update frequencyEvery 2 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.013.0
Further details — not scored
Size288 MB12 MB
Age rating4+4+
DeveloperPrepFE, Inc.gitClimbing LLC

Customer experience

PrepFE

All ratings57 ratings
Positive24.6%
Neutral0.0%
Negative75.4%
Written reviews42 reviews
Positive16.7%
Neutral0.0%
Negative83.3%

Thermo Jesus

All ratings4 ratings
Positive75.0%
Neutral0.0%
Negative25.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

6 purchases

PrepFE

One-time6
  • 1 Month Access Renewal$47.99
  • 1 Month Access2 variants$59.99
  • 3 Months Access Renewal$61.99
Show 3 more
  • 6 Months Access Renewal$75.99
  • 3 Months Access2 variants$79.99
  • 6 Months Access2 variants$99.99
3 purchases

Thermo Jesus

Subscriptions2
  • Monthly Subscription14 Days trial$1.991 Month
  • Semesterly (6 months)14 Days trial$7.996 Months
One-time1
  • Lifetime Access$9.99

Questions

Is PrepFE free?
PrepFE is free to download, with in-app purchases available.
Is Thermo Jesus free?
Thermo Jesus is free to download, with in-app purchases available.
Which has better reviews, PrepFE or Thermo Jesus?
Thermo Jesus is rated higher. PrepFE averages 2.0 out of 5 from 58 ratings, while Thermo Jesus averages 4.0 from 4 ratings.
Do PrepFE or Thermo Jesus have ads?
Neither PrepFE nor Thermo Jesus shows ads.
Which is updated more often, PrepFE or Thermo Jesus?
PrepFE ships an update every 2 months, and Thermo Jesus every 3 weeks. Most recently, PrepFE was updated on October 24, 2026 and Thermo Jesus on October 24, 2026.

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