# Zero/Sum vs Only One

The clearest difference is review sentiment: Only One at 100% against Zero/Sum's 54%. Only One also leads on rating (5.0 vs 4.2). Zero/Sum's advantage is price (Free vs $0.99) and update cadence (every 2 months vs every 39 months). On ads, in-app purchases and device support there is nothing between them.

Zero/Sum is free to download; Only One costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Only One holds the better App Store score, 5.0 against 4.2. That said, the two scores are not equally well evidenced: Zero/Sum has 27 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 54% of Zero/Sum's written reviews are positive against 100% of Only One's.

Zero/Sum ships an update every 2 months, Only One every 39 months. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Zero/Sum | Only One |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | [4.2 (27 ratings)](https://appshunter.io/ios/app/zerosum/id1200231665/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/only-one-a-logic-puzzle/id1619099640/reviews)** |
| Number of ratings | **27** | 2 |
| Positive reviews | 53.8% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 39 months |
| Monetization | **Free** | Paid |
| Size | 973 MB | 65 MB |
| Requires iOS | **8.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Sean Kearney](https://appshunter.io/developer/944858047) | [Kofi Austin](https://appshunter.io/developer/1495016623) |

## What reviewers say

### Zero/Sum

[App page](https://appshunter.io/ios/app/zerosum/id1200231665)

Solve mathematical puzzles to uncover a cure for cancer in this unique puzzle game. Experience an 80s action movie-inspired storyline with live-action cinematics and a variety of fresh puzzle mechanics. Features daily challenges and time trials.

**Highlights:** Unique and original puzzle gameplay, 80s action movie-inspired storyline, Full motion video cinematics with real actors, Variety of puzzle types (melting, number), Daily Challenge Mode with new puzzles, Time Trial mode

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

**In-app purchases:** none


### Only One

[App page](https://appshunter.io/ios/app/only-one-a-logic-puzzle/id1619099640)

This is a minimalist logic puzzle game where each level requires you to find a unique solution related to the number one. Explore diverse puzzles and receive hints if you get stuck for over 45 seconds.

**Highlights:** Minimalist logic puzzles, Unique solutions per level, Theme based on the number one, Variety of fun puzzles, In-game hints after 45 seconds

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

**In-app purchases:** none


## Frequently asked questions

### Is Zero/Sum free?

Zero/Sum is free to download, with no in-app purchases.

### Is Only One free?

Only One costs $0.99, with no in-app purchases.

### Which has better reviews, Zero/Sum or Only One?

Only One is rated higher. Zero/Sum averages 4.2 out of 5 from 27 ratings, while Only One averages 5.0 from 2 ratings.

### Do Zero/Sum or Only One have ads?

Neither Zero/Sum nor Only One shows ads.

### Which is updated more often, Zero/Sum or Only One?

Zero/Sum ships an update every 2 months, and Only One every 39 months. Most recently, Zero/Sum was updated on October 26, 2026 and Only One on October 24, 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.*