Comparison

Thermo Sudoku vs Sumaddle

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

Head to head
About

Thermo Sudoku

This app offers a unique twist on classic Sudoku with the addition of thermometer shapes. Digits must increase along the thermometer, creating new logical challenges and patterns. Enjoy 100 expertly crafted puzzles with hints from renowned Sudoku experts.

Highlights
  • 100 unique puzzles
  • Thermometer logic
  • Expert-crafted hints
  • Progressive difficulty
  • Star-based progression
Features
Read full description

***** MARCH UPDATE ***** 20 new puzzles, 100 puzzles total! ------------------------------------- Presented by Cracking The Cryptic, YouTube’s most popular Sudoku channel, comes a new game featuring one of the most popular puzzle types: Thermo Sudoku. How does Thermo Sudoku work? Well each sudoku grid contains thermometer shapes (often drawn to create themes) and digits on thermometers must increase as one moves further from the bulb end. The interactions between the thermometers leads to new logical ideas and patterns that completely refreshes the standard sudoku solving experience. As with their other games (‘Classic Sudoku’, ‘Sandwich Sudoku’ and ‘Chess Sudoku’), Simon Anthony and Mark Goodliffe (the hosts of Cracking The Cryptic) have personally crafted the hints for the puzzles. So you know that every puzzle has been play-tested by a human being to ensure that the sudoku is interesting and fun to solve. In Cracking The Cryptic’s games, players start with zero stars and earn stars by solving puzzles. The more puzzles you solve, the more stars you earn and the more puzzles you get to play. Only the most dedicated (and cleverest) sudoku players will finish all the puzzles. Of course the difficulty is carefully calibrated to ensure lots of puzzles at every level (from easy through to extreme). Anyone familiar with their YouTube channel will know that Simon and Mark take pride in teaching viewers to be better solvers and, in these games, they always craft the puzzles with the mindset of trying to help solvers improve their skills. Mark and Simon have both represented the UK many times at the World Sudoku Championship and you can find more of their puzzles (and lots of others) on the internet’s biggest sudoku channel Cracking The Cryptic. Features: 100 beautiful puzzles Hints crafted by Simon and Mark!

About

Sumaddle

This logic puzzle game transforms pencil-and-paper challenges into interactive brain teasers. Fit number combinations to clues using pure logic, with no mental arithmetic required. Enjoy over 150 free puzzles of varying difficulty, with built-in help and offline play.

Highlights
  • Interactive logic puzzles
  • Number combination fitting
  • Pure logic solving
  • Built-in help and mistake correction
  • Over 150 free puzzles
  • Offline play
  • Ad-free experience
Features
Read full description

This type of logical puzzle was first seen in the Japan Puzzle Championship 2006 and is sometimes known as Doppelblock, or Smashed Sums. When played with pencil and paper, these puzzles can be hard work to solve. Sumaddle changes that by transforming the puzzles into interactive brain teasers that unfold before your eyes. Each puzzle has a unique solution. Finding the solution involves fitting the number combinations to the clues. The app makes it easy to view the possible combinations, you don’t need to do any sums in your head. Instead, you are able to focus on using logic to narrow down the combinations and find a fitting arrangement. The puzzles come in a range of sizes and difficulties, to suit all levels of skill and puzzling purposes. Choose a small puzzle to idle away a minute or two while waiting in a queue, or a big puzzle to give your brain some exercise during a coffee break! Some reasons why you will enjoy playing Sumaddle: • more than 150 puzzles are included for free • all puzzles can be solved with pure logic, no mental arithmetic required • the sophisticated built-in help can explain the logical reasoning at each step and also fix mistakes if you go wrong • the built-in help is completely free, use it as much as you like • works offline (great for long journeys) • a high standard of accessibility, including comprehensive support for VoiceOver • ad-free play - there are absolutely no ads! IGRS age rating (Indonesia Game Rating System): 3+ Designed and developed in Winterthur, Switzerland

Screenshots

Thermo Sudoku3 screens
Sumaddle3 screens

Verdict

The call

The clearest difference is price: Sumaddle at Free against Thermo Sudoku's $4.99. Sumaddle also leads on update cadence (every 3 weeks vs every 4 months) and review sentiment (95% vs 82%). Thermo Sudoku's advantage is in-app purchases (none vs 10) and iOS requirement (11.0 vs 17.0). On rating, ads 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

Sumaddle is free to download; Thermo Sudoku costs $4.99 up front. Sumaddle sells 10 one-off in-app purchases. Thermo Sudoku asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for Thermo Sudoku against 4.9 for Sumaddle. That said, the two scores are not equally well evidenced: Sumaddle has 769 ratings behind it against 145, so its average is the more settled of the two. Written reviews are what separate them: 82% of Thermo Sudoku's written reviews are positive against 95% of Sumaddle's.

UpkeepUpdate frequency

Thermo Sudoku ships an update every 4 months, Sumaddle every 3 weeks. Both last shipped on November 11, 2026.

Scorecard7 real differences · 3 level
Thermo Sudoku versus Sumaddle: the parameters behind the verdict, then further details
ParameterThermo SudokuSumaddle
Price$4.99Free — better
Rating4.8 (145 ratings)4.9 (769 ratings) — better
Positive reviews82.5% of reviews94.9% of reviews — better
Number of ratings145769 — better
Update frequencyEvery 4 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS11.0 — better17.0
Further details — not scored
Size48 MB31 MB
Age rating4+4+
DeveloperNick CarneyJonathan Buchanan

Customer experience

Thermo Sudoku

All ratings145 ratings
Positive95.9%
Neutral0.7%
Negative3.4%
Written reviews57 reviews
Positive82.5%
Neutral7.0%
Negative10.5%

Sumaddle

All ratings769 ratings
Positive98.3%
Neutral0.7%
Negative1.0%
Written reviews98 reviews
Positive94.9%
Neutral1.0%
Negative4.1%

User reviews

Thermo Sudoku

From 145 App Store ratings

What we love

  • 👍 Well-made, challenging puzzles
  • 💡 Handcrafted, unique puzzles
  • 👍 Great logic and learning
  • 👍 Intuitive and beautiful interface
  • 👍 Excellent user experience

Room to improve

  • 🐛 Timer glitch/inaccurate tracking
  • 🐛 Awful controls
  • 🐛 Clues sometimes illogical
  • 🐛 Puzzles too hard/convoluted
  • 🐛 Locked puzzles behind easy ones

Sumaddle

From 769 App Store ratings

What we love

  • 👍 Fun and challenging game
  • 👍 Clean and intuitive interface
  • 👍 Helpful hint system
  • 🚀 No ads or data collection
  • 💡 Unique puzzle concept

Room to improve

  • 🐛 Automatic hints can be intrusive
  • 🐛 Inability to replay completed puzzles
  • 💡 Need more free/sample puzzles
  • 💡 Difficulty progression could be improved

Bugs and requests

Thermo Sudoku

Reported bugs

11 issues
  • Timer adds incorrect hours/minutes
  • Timer adds 44 seconds when notifications are pulled down
  • Timer jumps when exiting/re-entering app
  • Wrong number put into box when leaving and loading app
  • Clues do not stand up to logic
Show 6 more
  • Controls are bad
  • Erase function does not work as expected
  • Keyboard navigation incomplete
  • Arrow keys often don't register
  • Puzzle 24 impossible without cheating
  • Multiple solutions found in puzzles

Requested features

14 requests
  • Fix timer glitch
  • Improve controls
  • Ensure logical clues
  • Add more puzzles
  • Unlock all puzzles
Show 9 more
  • Improve hint clarity
  • Add synchronization across devices
  • Improve keyboard navigation
  • Add split view mode
  • Revert to old menu design
  • Allow reading hints while viewing board
  • Grey out used numbers
  • Improve erase function
  • Offer a theme similar to Chess Sudoku

Sumaddle

Reported bugs

2 issues
  • Losing progress when minimizing the app
  • Inconsistent difficulty ratings

Requested features

4 requests
  • Ability to selectively pencil in notes
  • More difficult puzzle options
  • Synced progress across devices
  • Detailed statistics and leaderboard

In-app purchases

None

Thermo Sudoku

No in-app purchases

10 purchases

Sumaddle

One-time10
  • Crafty, Pack 1$0.99
  • Crafty, Pack 2$0.99
  • Crafty, Pack 3$0.99
Show 7 more
  • Sneaky, Pack 1$0.99
  • Sneaky, Pack 2$0.99
  • Sneaky, Pack 3$0.99
  • Tricky, Pack 1$0.99
  • Tricky, Pack 2$0.99
  • Tricky, Pack 3$0.99
  • Puzzle Generator$9.99

Questions

Is Thermo Sudoku free?
Thermo Sudoku costs $4.99, with no in-app purchases.
Is Sumaddle free?
Sumaddle is free to download, with in-app purchases available.
Which has better reviews, Thermo Sudoku or Sumaddle?
Sumaddle is rated higher. Thermo Sudoku averages 4.8 out of 5 from 145 ratings, while Sumaddle averages 4.9 from 769 ratings.
Do Thermo Sudoku or Sumaddle have ads?
Neither Thermo Sudoku nor Sumaddle shows ads.
Which is updated more often, Thermo Sudoku or Sumaddle?
Thermo Sudoku ships an update every 4 months, and Sumaddle every 3 weeks. Most recently, Thermo Sudoku was updated on November 11, 2026 and Sumaddle on November 11, 2026.

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