# PrepFE vs Engineering Formulas

The clearest difference is iOS requirement: PrepFE at 13.0 against Engineering Formulas's 15.1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. PrepFE sells 6 one-off in-app purchases and Engineering Formulas sells 3 in-app purchases, starting at $4.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 8, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | PrepFE | Engineering Formulas |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.0 (57 ratings)](https://appshunter.io/ios/app/prepfe-fe-mechanical-prep/id1455746709/reviews)** | — |
| Number of ratings | **57** | — |
| Positive reviews | 16.7% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Free with in-app purchases | — |
| Size | 288 MB | 45 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [PrepFE, Inc.](https://appshunter.io/developer/1499557437) | [Mobin Akhter](https://appshunter.io/developer/1812505286) |

## What reviewers say

### PrepFE

[App page](https://appshunter.io/ios/app/prepfe-fe-mechanical-prep/id1455746709)

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:** Vision Pro support

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Month Access Renewal | $47.99 | one-time |
| 1 Month Access | $59.99 | one-time |
| 3 Months Access Renewal | $61.99 | one-time |
| 6 Months Access Renewal | $75.99 | one-time |
| 3 Months Access | $79.99 | one-time |
| 6 Months Access | $99.99 | one-time |


### Engineering Formulas

[App page](https://appshunter.io/ios/app/engineering-formulas-engiref/id6758258119)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Premium | $4.99 | per 7 days |
| Yearly Premium | $29.99 | per year |
| Lifetime Access | $54.99 | one-time |


## Frequently asked questions

### Is PrepFE free?

PrepFE is free to download, with in-app purchases available.

### Is Engineering Formulas free?

Engineering Formulas is free to download, with in-app purchases available.

### Do PrepFE or Engineering Formulas have ads?

Neither PrepFE nor Engineering Formulas shows ads.

### Which is updated more often, PrepFE or Engineering Formulas?

PrepFE ships an update every 2 months, and Engineering Formulas every 2 months. Most recently, PrepFE was updated on October 8, 2026 and Engineering Formulas on October 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*