Comparison

Fast Sudoku Solver vs Smart Keys

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Fast Sudoku Solver

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
Read full description

Solve any Sudoku puzzle. If you stuck on any sudoku, just fill out the board and the solution instantly in one click!

About

Smart Keys

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
Read full description

Smart Keys makes writing easier and more enjoyable. As bilinguals passionate about languages, we created this smart keyboard to help anyone communicate fluently and effortlessly. Whether it’s polishing grammar, adding style, or translating instantly, Smart Keys simplifies your writing experience. It’s a game-changer for ESL users and those balancing multilingual conversations, bringing natural flow to every message. Smart Keys is designed to help you communicate naturally, without losing your unique style. From keeping in touch with loved ones to managing multilingual conversations at work, Smart Keys, as your go-to writing tools, make switching between languages a breeze. NOW A SCREEN TRANSLATOR AND SMART REPLY - On-the-Fly Translation: Instantly translate incoming messages, screenshots, or entire conversation threads, perfect for TikTok refugees on RedNote 小红书 (Xiaohongshu). - Smart Reply Suggestions: Get quick, context-aware responses in any language. - Image-Based Messaging: Upload an image and let Smart Keys generate text for you. SMART KEYS + IPAD BLUETOOTH KEYBOARD = MAGIC! You can now use Smart Keys seamlessly with your Bluetooth keyboard like a pro. It’s almost like having a smart Touch Bar for your external iPad keyboard, enhancing your typing experience with effortless fluency and creativity! CREATE YOUR OWN GENERATIVE AI KEY Now, we’re taking it even further with a new feature: the ability to create your own custom keys. Smart Keys gives you full creative control, letting you design keys that suit your unique writing style and needs. Make your keys private or share them publicly, Smart Keys is all about making writing exactly what you want it to be. WORK FASTER - Proofread: Skip the copy-paste routine and proofread directly as you type. It’s fast, easy, and seamless, thanks to our efficient writing tools. - Tone Customization: Effortlessly shift between casual and formal tones, ensuring your message is just right, every time. - Translate: Break down language barriers with instant, accurate translations that make global communication simple. - Text-to-Speech: Bring your words to life by instantly transforming your text into clear, natural speech. Communicate with impact using our new voice keys, designed to add another dimension to your writing. PLAY SMARTER - Pickup Lines: Add a touch of charm to your conversations with creative, fun pickup lines, all at your fingertips. - Jokes: Brighten your day with a quick joke—because who doesn’t need a little laugh? - Horoscopes: Get a daily dose of cosmic insight with quick horoscope readings, perfect for sharing. - Make it Rhyme: Turn your text into poetry with a single tap, because creativity should be easy with the right writing tools. - Kaomoji: Express yourself effortlessly with kaomojis, adding personality to your messages. WORKS WHERE YOU DO No matter where you’re typing, Smart Keys works across multiple platforms, so you can enjoy all these writing tools wherever you are. WHY CHOOSE SMART KEYS - Enhance Your Writing: Create clear, confident messages with ease, using our writing tools. - Expand Your Vocabulary: Discover smarter word choices effortlessly with our writing tools. - Save Time: Focus on what you love by spending less time editing, thanks to our writing tools. - Sound Fluent: Effortlessly polish your writing to sound natural and fluent with our writing tools. - Enjoy Writing: Transform writing from a chore into a simple, joyful experience with Smart Keys' advanced writing tools. FREE & PRO PLANS Start with our Free Plan and see how Smart Keys can simplify your writing. When you’re ready for even more effortless creativity, unlock additional features with our Pro Plan. Whether you choose Free or Pro, Smart Keys and its writing tools are here to make writing easier for you. Terms of Service: https://www.smartkeys.so/terms Privacy Policy: https://www.smartkeys.so/privacy

Screenshots

Fast Sudoku Solver3 screens
Smart Keys4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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

Scorecard8 real differences · 2 level
Fast Sudoku Solver versus Smart Keys: the parameters behind the verdict, then further details
ParameterFast Sudoku SolverSmart Keys
PriceFreeFree
Rating5.0 (4 ratings) — better4.6 (535 ratings)
Positive reviews100.0% of reviews — better43.2% of reviews
Number of ratings4535 — better
Update frequencyEvery 4 monthsEvery 2 weeks — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad, Mac — better
Requires iOS10.0 — better17.0
Further details — not scored
Size47 MB39 MB
Age rating4+9+
DeveloperNikita TeplyakovFireflow Creative Collective LLC

Customer experience

Fast Sudoku Solver

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Smart Keys

All ratings535 ratings
Positive89.3%
Neutral3.6%
Negative7.1%
Written reviews37 reviews
Positive43.2%
Neutral16.2%
Negative40.5%

Bugs and requests

Fast Sudoku Solver

Not enough reviews yet to summarise bugs or requests.

Smart Keys

Reported bugs

5 issues
  • 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

6 requests
  • 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
Show 1 more
  • Better autocorrect functionality

In-app purchases

None

Fast Sudoku Solver

No in-app purchases

10 purchases

Smart Keys

Subscriptions8
  • Smart Keys Pro3 Days trial$4.997 Days
  • Smart Keys Pro Desktop3 Days trial$4.997 Days
  • Smart Keys Voice3 Days trial$4.997 Days
Show 5 more
  • Smart Keys Pro3 Days trial$12.491 Month
  • Smart Keys Pro Desktop3 Days trial$12.991 Month
  • Smart Keys Pro$49.901 Year
  • Smart Keys Pro3 Days trial$69.991 Year
  • Smart Keys Pro Desktop3 Days trial$99.991 Year
One-time2
  • Lifetime$39.99
  • Smart Keys Pro$123.99

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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