# OS Interview Questions vs MemoCard Ace

The clearest difference is rating: MemoCard Ace at 5.0 against OS Interview Questions's 1.0. MemoCard Ace also leads on ads (none vs shown) and update cadence (every 3 weeks vs every 95 months). On price, in-app purchases, monetization model and device support there is nothing between them.

Both are free to download. OS Interview Questions sells 1 one-off in-app purchase and MemoCard Ace sells 3 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

MemoCard Ace holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

OS Interview Questions ships an update every 95 months, MemoCard Ace every 3 weeks. The most recent releases landed on June 25, 2026 and August 10, 2026 respectively.

## The numbers

| Metric | OS Interview Questions | MemoCard Ace |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/os-interview-questions/id1070986818/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/memocard-ace/id1660053684/reviews)** |
| Number of ratings | 1 | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 95 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | Freemium |
| Size | 16 MB | 17 MB |
| Requires iOS | **14.0** | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [RAVINDHIRAN SUMITHRA](https://appshunter.io/developer/1571016391) | [傲 薛](https://appshunter.io/developer/1531236421) |

## What reviewers say

### OS Interview Questions

[App page](https://appshunter.io/ios/app/os-interview-questions/id1070986818)

Learn fundamental operating system concepts and interview questions with this educational app. It offers a user-friendly interface to explore topics, save favorites, and customize your reading experience. Sharpen your technical knowledge for career advancement.

**Highlights:** Operating system overview, Functions of operating systems, Types of operating systems, Embedded OS interview questions, User-friendly interface, Personalized library for favorites, Customizable themes and fonts

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OS Interview Questions | $3.99 | one-time |


### MemoCard Ace

[App page](https://appshunter.io/ios/app/memocard-ace/id1660053684)

This study tool aids memorization for various subjects, including languages and coding challenges. It utilizes spaced repetition and the forgetting curve to enhance information retention. Track progress and achieve learning goals with this versatile educational aid.

**Highlights:** Spaced repetition system, Forgetting curve optimization, Language learning tools, LeetCode submission history tracking, General information memorization, Progress tracking

**Features:** Family Sharing

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $0.99 | per month |
| Yearly Premium | $3.99 | per year |
| Lifetime Premium | $6.99 | one-time |


## Frequently asked questions

### Is OS Interview Questions free?

OS Interview Questions is free to download, with in-app purchases available.

### Is MemoCard Ace free?

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

### Which has better reviews, OS Interview Questions or MemoCard Ace?

MemoCard Ace is rated higher. OS Interview Questions averages 1.0 out of 5 from 1 ratings, while MemoCard Ace averages 5.0 from 4 ratings.

### Do OS Interview Questions or MemoCard Ace have ads?

OS Interview Questions shows ads; MemoCard Ace does not.

### Which is updated more often, OS Interview Questions or MemoCard Ace?

OS Interview Questions ships an update every 95 months, and MemoCard Ace every 3 weeks. Most recently, OS Interview Questions was updated on June 25, 2026 and MemoCard Ace on August 10, 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.*