# OnePrep vs Ace AP STEM

The clearest difference is review sentiment: Ace AP STEM at 100% against OnePrep's 41%. Ace AP STEM also leads on in-app purchases (none vs 24) and ads (none vs shown). OnePrep's advantage is update cadence (every 5 days vs every 3 months) and ratings volume (714 vs 3). On price, device support and iOS requirement there is nothing between them.

Both are free to download. OnePrep sells 24 in-app purchases, starting at $28.49 per 7 days. Ace AP STEM asks for nothing beyond the download.

Ace AP STEM holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: OnePrep has 714 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 41% of OnePrep's written reviews are positive against 100% of Ace AP STEM's.

OnePrep ships an update every 5 days, Ace AP STEM every 3 months. The most recent releases landed on October 28, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | OnePrep | Ace AP STEM |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (714 ratings)](https://appshunter.io/ios/app/oneprep-sat-and-act-prep/id6755932961/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/ace-ap-stem/id6780169317/reviews)** |
| Number of ratings | **714** | 3 |
| Positive reviews | 40.7% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 5 days** | Every 3 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 88 MB | 24 MB |
| Requires iOS | **15.1** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MyDojo Inc.](https://appshunter.io/developer/1854476769) | [Linh Do](https://appshunter.io/developer/6780169319) |

## What reviewers say

### OnePrep

[App page](https://appshunter.io/ios/app/oneprep-sat-and-act-prep/id6755932961)

Prepare for the SAT with a comprehensive study tool. Access thousands of practice questions, realistic mock exams, and AI-powered feedback. Get personalized guidance from an AI tutor to identify and improve weak areas for your dream score.

**Highlights:** Thousands of SAT-style practice questions, Realistic timed mock exams, Instant AI feedback and grading, Personalized study guidance, Progress tracking, Cross-device compatibility

**In-app purchases (24)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OnePrep Pro (1 Week) | $28.49 | per 7 days |
| OnePrep Plus (1 month) | $89.99 | per month |
| OnePrep Pro (1 Month) | $99.99 | per month |
| OnePrep Pro – Monthly | $99.99 | per month |
| OnePrep Plus (3 months) | $239.00 | per 3 months |
| OnePrep Pro (3 Months) | $269.00 | per 3 months |
| OnePrep Pro – 3 Months | $269.00 | per 3 months |
| OnePrep Plus (6 months) | $354.99 | per 6 months |
| OnePrep Pro (6 Months) | $414.99 | per 6 months |
| OnePrep Pro – 6 Months | $414.99 | per 6 months |
| OnePrep Plus (1 year) | $469.00 | per year |
| OnePrep Pro (1 Year) | $589.00 | per year |
| OnePrep Pro – Yearly | $589.00 | per year |
| OnePrep Plus Exam Pass (8-14 Days) | $80.00 | one-time |
| OnePrep Plus Exam Pass (15-28 Days) | $85.00 | one-time |
| OnePrep Pro Exam Pass (0-7 Days) | $89.00 | one-time |
| OnePrep Pro Exam Pass (8-14 Days) | $90.00 | one-time |
| OnePrep Pro Exam Pass (15-28 Days) | $95.00 | one-time |
| OnePrep Pro Exam Pass (29-30 Days) | $99.00 | one-time |
| OnePrep Pro Exam Pass (31-44 Days) | $134.99 | one-time |
| OnePrep Pro Exam Pass (45-58 Days) | $174.99 | one-time |
| OnePrep Pro Exam Pass (59-72 Days) | $209.99 | one-time |
| OnePrep Plus Exam Pass (8-10 Mos) | $429.00 | one-time |
| OnePrep Plus Exam Pass (10+ Months) | $464.99 | one-time |


### Ace AP STEM

[App page](https://appshunter.io/ios/app/ace-ap-stem/id6780169317)

This study toolkit helps AP STEM students deeply understand concepts and solve problems. It offers step-by-step solutions, gradual hints, and concept notes. Organize your learning with a personal study library and practice with related problems.

**Highlights:** Step-by-step problem solving, Gradual hints for self-solving, Generate concept notes, Personalized study library, Practice with related problems, Customizable study buddy

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

**In-app purchases:** none


## Frequently asked questions

### Is OnePrep free?

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

### Is Ace AP STEM free?

Ace AP STEM is free to download, with no in-app purchases.

### Which has better reviews, OnePrep or Ace AP STEM?

Ace AP STEM is rated higher. OnePrep averages 4.7 out of 5 from 714 ratings, while Ace AP STEM averages 5.0 from 3 ratings.

### Do OnePrep or Ace AP STEM have ads?

OnePrep shows ads; Ace AP STEM does not.

### Which is updated more often, OnePrep or Ace AP STEM?

OnePrep ships an update every 5 days, and Ace AP STEM every 3 months. Most recently, OnePrep was updated on October 28, 2026 and Ace AP STEM on October 20, 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.*