# One By One vs BadAdmin

The clearest difference is review sentiment: One By One at 91% against BadAdmin's 0%. One By One also leads on rating (4.8 vs 2.0) and ratings volume (77 vs 1). BadAdmin's advantage is in-app purchases (none vs 3). On price, ads and device support there is nothing between them.

Both are free to download. One By One sells 3 in-app purchases, starting at $1.99 per month. BadAdmin asks for nothing beyond the download.

One By One holds the better App Store score, 4.8 against 2.0. That said, the two scores are not equally well evidenced: One By One has 77 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 91% of One By One's written reviews are positive against 0% of BadAdmin's.

One By One ships an update every 2 weeks, BadAdmin every 5 weeks. The most recent releases landed on October 13, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | One By One | BadAdmin |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (77 ratings)](https://appshunter.io/ios/app/one-by-one-mental-math/id1555846023/reviews)** | [2.0 (1 ratings)](https://appshunter.io/ios/app/badadmin/id1567736058/reviews) |
| Number of ratings | **77** | 1 |
| Positive reviews | **90.9% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | **Every 2 weeks** | Every 5 weeks |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 64 MB | 24 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Brice Brown](https://appshunter.io/developer/1555846025) | [Torben Steen](https://appshunter.io/developer/1452072129) |

## What reviewers say

### One By One

[App page](https://appshunter.io/ios/app/one-by-one-mental-math/id1555846023)

Practice arithmetic, algebra, trigonometry, and calculus with a retro-style math game. Level up by solving problems, unlock new challenges, and compete on leaderboards. Enhance your skills with artifacts and strategic upgrades.

**Highlights:** Randomly generated math problems, Leveling system with unlockable content, Practice arithmetic, algebra, trigonometry, and calculus, Retro ASCII art and music style, Leaderboards and achievements, Math artifacts and upgrades, AI battle mode for targeted practice

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Support | $1.99 | per month |
| Yearly Support | $12.99 | per year |
| Lifetime Supporter pass | $19.99 | one-time |


### BadAdmin

[App page](https://appshunter.io/ios/app/badadmin/id1567736058)

Manage servers and minimize downtime in this simulation game. React quickly to server failures by restarting them to keep operations smooth. Your goal is to achieve the lowest possible server downtime.

**Highlights:** Server management simulation, Minimize server downtime, React to server failures, Restart failed servers, Achieve low downtime

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is One By One free?

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

### Is BadAdmin free?

BadAdmin is free to download, with no in-app purchases.

### Which has better reviews, One By One or BadAdmin?

One By One is rated higher. One By One averages 4.8 out of 5 from 77 ratings, while BadAdmin averages 2.0 from 1 ratings.

### Do One By One or BadAdmin have ads?

Both One By One and BadAdmin show ads.

### Which is updated more often, One By One or BadAdmin?

One By One ships an update every 2 weeks, and BadAdmin every 5 weeks. Most recently, One By One was updated on October 13, 2026 and BadAdmin on October 12, 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.*