# Fast Sudoku Solver vs Smart Keys

The clearest difference is review sentiment: Fast Sudoku Solver at 100% against Smart Keys's 43%. Fast Sudoku Solver also leads on in-app purchases (none vs 10) and ads (none vs shown). Smart Keys's advantage is update cadence (every 2 weeks vs every 4 months) and ratings volume (535 vs 4). On price and device support there is nothing between them.

Both are free to download. Smart Keys sells 10 in-app purchases, starting at $4.99 per 7 days. Fast Sudoku Solver asks for nothing beyond the download.

Fast Sudoku Solver holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Smart Keys has 535 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 100% of Fast Sudoku Solver's written reviews are positive against 43% of Smart Keys's.

Fast Sudoku Solver ships an update every 4 months, Smart Keys every 2 weeks. Both last shipped on October 24, 2026.

## The numbers

| Metric | Fast Sudoku Solver | Smart Keys |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/fast-sudoku-solver/id1469739609/reviews)** | [4.6 (535 ratings)](https://appshunter.io/ios/app/smart-keys-writing-tools/id6602882160/reviews) |
| Number of ratings | 4 | **535** |
| Positive reviews | **100.0% of reviews** | 43.2% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 47 MB | 39 MB |
| Requires iOS | **10.0** | 17.0 |
| Devices | iPhone, iPod | **iPhone, iPad, Mac** |
| Age rating | 4+ | 9+ |
| Developer | [Nikita Teplyakov](https://appshunter.io/developer/1469739608) | [Fireflow Creative Collective LLC](https://appshunter.io/developer/1755305724) |

## What reviewers say

### Fast Sudoku Solver

[App page](https://appshunter.io/ios/app/fast-sudoku-solver/id1469739609)

Instantly solve any Sudoku puzzle with a single click. Simply input the current state of the board, and the application will provide the complete solution.

**Highlights:** Instant Sudoku solving, One-click solution, Input board state, Supports any Sudoku puzzle

**Features:** macOS Compatibility

**In-app purchases:** none


### Smart Keys

[App page](https://appshunter.io/ios/app/smart-keys-writing-tools/id6602882160)

This AI-powered keyboard enhances your writing by offering instant translation, grammar correction, and smart reply suggestions. It also features text generation from images, custom AI key creation, and text-to-speech capabilities, making communication effortless across languages and platforms.

**Highlights:** On-the-fly translation, Smart reply suggestions, Image-based text generation, Custom generative AI keys, Real-time proofreading, Tone customization, Text-to-speech

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Smart Keys Pro | $4.99 | per 7 days |
| Smart Keys Pro Desktop | $4.99 | per 7 days |
| Smart Keys Voice | $4.99 | per 7 days |
| Smart Keys Pro | $12.49 | per month |
| Smart Keys Pro Desktop | $12.99 | per month |
| Smart Keys Pro | $49.90 | per year |
| Smart Keys Pro | $69.99 | per year |
| Smart Keys Pro Desktop | $99.99 | per year |
| Lifetime | $39.99 | one-time |
| Smart Keys Pro | $123.99 | one-time |

**What reviewers like**

- 🚀 Fast and efficient grammar correction
- ✍️ Excellent proofreading capabilities
- 🎯 Intelligent shortcuts save time
- 🌍 Multi-language translation support
- 👍 User-friendly and simple interface

**What reviewers complain about**

- 💰 Expensive pricing model
- 🔐 Requests excessive permissions (credit card, address data)
- ⏳ Severe daily usage limits on free version
- 🚫 Paywall-heavy monetization strategy
- 🐌 Keyboard occasionally laggy

**Reported bugs**

- Connection issues despite active internet connection
- Keyboard lags during use
- Autocorrect performs poorly compared to Apple's native option
- App requests excessive permissions unrelated to keyboard functionality
- Translation accuracy issues reported

**Requested features**

- Add Arabic language support
- Translate incoming messages from other users
- Reduce daily usage limits or offer ad-supported free version
- Lower lifetime pricing (previously $35, now $124)
- Improve keyboard responsiveness


## Frequently asked questions

### Is Fast Sudoku Solver free?

Fast Sudoku Solver is free to download, with no in-app purchases.

### Is Smart Keys free?

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

### Which has better reviews, Fast Sudoku Solver or Smart Keys?

Fast Sudoku Solver is rated higher. Fast Sudoku Solver averages 5.0 out of 5 from 4 ratings, while Smart Keys averages 4.6 from 535 ratings.

### Do Fast Sudoku Solver or Smart Keys have ads?

Smart Keys shows ads; Fast Sudoku Solver does not.

### Which is updated more often, Fast Sudoku Solver or Smart Keys?

Fast Sudoku Solver ships an update every 4 months, and Smart Keys every 2 weeks. Most recently, Fast Sudoku Solver was updated on October 24, 2026 and Smart Keys 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.*