# Grammar Ninja vs Osmo Numbers

The clearest difference is review sentiment: Grammar Ninja at 100% against Osmo Numbers's 33%. Grammar Ninja also leads on rating (5.0 vs 3.8) and iOS requirement (13.0 vs 15.0). Osmo Numbers's advantage is in-app purchases (none vs 6) and ads (none vs shown). On price, ratings volume, monetization model and device support there is nothing between them.

Both are free to download. Grammar Ninja sells 6 one-off in-app purchases. Osmo Numbers asks for nothing beyond the download.

Grammar Ninja holds the better App Store score, 5.0 against 3.8. Both are backed by a comparable volume of ratings — 52 and 146 respectively. Written reviews point the same way: 100% of Grammar Ninja's written reviews are positive against 33% of Osmo Numbers's.

Grammar Ninja ships an update every 8 months, Osmo Numbers every 2 months. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Grammar Ninja | Osmo Numbers |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (52 ratings)](https://appshunter.io/ios/app/grammar-ninja/id1443711891/reviews)** | [3.8 (146 ratings)](https://appshunter.io/ios/app/osmo-numbers/id1531762562/reviews) |
| Number of ratings | 52 | **146** |
| Positive reviews | **100.0% of reviews** | 33.3% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 8 months | **Every 2 months** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 179 MB | 358 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Greg Lieberman](https://appshunter.io/developer/1596441353) | [Tangible Play](https://appshunter.io/developer/799157444) |

## What reviewers say

### Grammar Ninja

[App page](https://appshunter.io/ios/app/grammar-ninja/id1443711891)

Engage in a word game where you identify grammatically correct sentences by targeting specific words with ninja stars. Hone your grammar skills to become a master word ninja.

**Highlights:** Target words in sentences, Identify grammatically correct sentences, Improve grammar skills, Word-based ninja game

**Features:** macOS Compatibility

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 100 Diamonds | $0.99 | one-time |
| 550 Diamonds | $4.99 | one-time |
| 1200 Diamonds | $9.99 | one-time |
| 2500 Diamonds | $19.99 | one-time |
| 5200 Diamonds | $39.99 | one-time |
| 15000 Diamonds | $99.99 | one-time |

**What reviewers like**

- 👍 Fun and engaging gameplay
- 💡 Educational and improves grammar
- 🚀 Great for all ages
- ✨ Visually appealing graphics
- ✅ Easy to use and understand

**What reviewers complain about**

- ↔️ Limited side-to-side movement on iPad

**Requested features**

- Side-to-side movement for iPad


### Osmo Numbers

[App page](https://appshunter.io/ios/app/osmo-numbers/id1531762562)

Engage in hands-on math activities with physical tiles that interact with your device. Solve problems to collect virtual fish, learn geography, and explore marine biology in a fun, stress-free environment.

**Highlights:** Hands-on play with physical tiles, Counting, addition, subtraction, multiplication, Collect over 100 virtual fish, Learn geography and marine biology, Real-time feedback, Stress-free learning environment

**In-app purchases:** none

**What reviewers like**

- 👍 Great way to practice math
- 👍 Kids enjoy it
- 👍 Fun concept
- 👍 Cute graphics and interactive things
- 👍 Hands-on learning

**What reviewers complain about**

- 🐛 App glitches frequently
- 🐛 App crashes
- 🐛 Game doesn't register tiles
- 🐛 Not compatible with certain iPads
- 🐛 Codes not working

**Reported bugs**

- App glitches
- App crashes
- Game will not register tiles
- Reflector not sensing tiles
- App won't open on old iPads

**Requested features**

- Increase timer duration
- Add more drawing games
- Add voice reading for math problems
- Improve tile sensing accuracy
- Make game go slower


## Frequently asked questions

### Is Grammar Ninja free?

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

### Is Osmo Numbers free?

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

### Which has better reviews, Grammar Ninja or Osmo Numbers?

Grammar Ninja is rated higher. Grammar Ninja averages 5.0 out of 5 from 52 ratings, while Osmo Numbers averages 3.8 from 146 ratings.

### Do Grammar Ninja or Osmo Numbers have ads?

Grammar Ninja shows ads; Osmo Numbers does not.

### Which is updated more often, Grammar Ninja or Osmo Numbers?

Grammar Ninja ships an update every 8 months, and Osmo Numbers every 2 months. Most recently, Grammar Ninja was updated on October 26, 2026 and Osmo Numbers on October 24, 2026.

---

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