Comparison

Sumaddle vs Stackdown

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

Head to head
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

About

Stackdown

Uncover six five-letter words hidden within a stack of tiles. Strategically select tiles, revealing new possibilities with each word found. Enjoy a daily puzzle, a vast archive, and practice modes, all playable offline.

Highlights
  • Uncover hidden five-letter words
  • Strategic tile selection
  • Daily puzzles and archive
  • Offline play
  • Spoiler-free sharing
  • Practice modes
Features
Read full description

Six five-letter words are buried in a stack of thirty tiles. Dig them out, one at a time, until the stack is gone. Only tiles with nothing resting on top of them can be picked. Take one and the tiles beneath may come free — so every word you find opens up the next. 【How It Works】 Tap free tiles to spell a word, in order. Find all six words to clear the stack. Stuck? Swipe the hint slider for a clue about the current word. Finish without hints and you earn all five stars. 【Only One Word Ever Fits】 This is the part that makes the puzzle work. At any moment there is exactly one word you can build from the free tiles — and only one set of tiles that builds it. Every stack in the game has been checked by an independent solver that walks every legal move, so you will never spell a real word and be told you are wrong. 【A Daily, Plus a Deep Archive】 A new stack arrives every day, with a streak to keep. Hundreds of past stacks stay playable in the archive, no account needed, and three hundred practice stacks wait in easy, medium and hard. Badges, best times, and a timer you can leave switched off round out the record. 【Share Your Front Page】 Every solve prints a result card — your time, your stars, your streak — ready to share with friends, with a spoiler-free option that hides the answers. Same stack, same six words: who digs out faster? 【Built to Be Pleasant】 Stackdown works fully offline, with no sign-in and no server. There are no forced ads in the middle of a puzzle, and a single purchase removes ads for good. Full iPad support, in light and dark. If you play the daily Stackdown web puzzle, this is that game on your phone: the whole back catalogue in your pocket, a proper share card, and somewhere to keep your streak. Stackdown is not affiliated with Waffle Studio or Puzzlist. 【Terms of Use (EULA)】 https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Sumaddle3 screens
Stackdown4 screens

Verdict

The call

The clearest difference is review sentiment: Sumaddle at 95% against Stackdown's 0%. Sumaddle also leads on ads (none vs shown). Stackdown's advantage is update cadence (every 8 days vs every 3 weeks). On price, in-app purchases, monetization model 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. Sumaddle sells 15 one-off in-app purchases and Stackdown sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Sumaddle ships an update every 3 weeks, Stackdown every 8 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

Scorecard3 real differences · 7 level
Sumaddle versus Stackdown: the parameters behind the verdict, then further details
ParameterSumaddleStackdown
PriceFreeFree
Rating4.9 (769 ratings) — better—
Positive reviews94.9% of reviews — better0.0% of reviews
Number of ratings769 — better—
Update frequencyEvery 3 weeksEvery 8 days — better
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size31 MB13 MB
Age rating4+4+
DeveloperJonathan BuchananIkuhei Kure

Customer experience

Sumaddle

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

Stackdown

Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Bugs and requests

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

Stackdown

Not enough reviews yet to summarise bugs or requests.

In-app purchases

15 purchases

Sumaddle

One-time15
  • Quirky, Pack 5$0.99
  • Very Difficult Puzzles$0.99
  • Quirky, Pack 1$0.99
Show 12 more
  • Premium 9x9 Puzzles, Pack 1$0.99
  • Crafty, Pack 1$0.99
  • Crafty, Pack 2$0.99
  • Crafty, Pack 3$0.99
  • 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
  • Assorted Puzzles$0.99
  • Puzzle Generator$9.99
1 purchases

Stackdown

One-time1
  • Premium$4.99

Questions

Is Sumaddle free?
Sumaddle is free to download, with in-app purchases available.
Is Stackdown free?
Stackdown is free to download, with in-app purchases available.
Do Sumaddle or Stackdown have ads?
Stackdown shows ads; Sumaddle does not.
Which is updated more often, Sumaddle or Stackdown?
Sumaddle ships an update every 3 weeks, and Stackdown every 8 days. Most recently, Sumaddle was updated on October 24, 2026 and Stackdown on October 25, 2026.

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