Comparison

Data Structure Display vs Codelet

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

Head to head
About

Data Structure Display

Explore and learn data structures through dynamic debugging and visual observation of changes. This app covers linear structures, trees, graphs, and recursive algorithms like the Tower of Hanoi, offering interactive learning experiences.

Highlights
  • Dynamic data structure debugging
  • Visual observation of data structure changes
  • Learn linear structures (arrays, lists, queues, stacks)
  • Explore tree structures (binary, AVL, red-black, heap)
  • Understand graph structures and algorithms
  • Debug recursive algorithms like Tower of Hanoi
Features
Read full description

A novel data structure learning app, the most significant feature is that you can dynamically debug the data structure in this app, and visually observe the changes in the data structure during the operation. In this app you can learn the following data structures: 1. Linear structures, including arrays, linked lists, queues, stacks. Linear structures are the basis for other advanced data structures, as fine as advanced algorithms. 2. Tree structures, including binary tree, binary search tree, AVL tree, red-black tree, and heap. In this app, you can dynamically debug three traversals of the binary tree (including non-recursive traversal implementations), searching in the tree, balance adjustments in the AVL tree and red-black tree, and heap sorting. Give you the ability of handwritten red-black trees. 3. Graph structure, including the adjacency list storage representation of the graph structure, depth-first search and breadth-first search, finding the Euler path in the graph, topological sorting, maximum connected components, minimum spanning tree problem, and shortest single source Path problem. It also provides dynamic debugging of these classic graph algorithms. 4. The data structure introductory class will talk about the problem of the Tower of Hanoi. The algorithm that solves this problem is often recursive. This app provides dynamic debugging of the Tower of Hanoi problem, so you can no longer be confused about the recursive calls of the Tower of Hanoi.

About

Codelet

Prepare for technical interviews by identifying core coding patterns and analyzing your performance. Practice coding questions conveniently to improve your skills and pinpoint areas for growth.

Highlights
  • Identify core patterns
  • Analyze approaches
  • Track performance
  • Identify improvement areas
  • Practice coding questions
  • Anytime, anywhere practice
Read full description

∙ Identify and analyze the core patterns and approaches ∙ View how well you’re doing and where you can improve ∙ Practice coding questions anywhere and anytime

Screenshots

Data Structure Display4 screens
Codelet4 screens

Verdict

The call

The clearest difference is in-app purchases: Codelet at none against Data Structure Display's 1. Codelet also leads on rating (4.7 vs 4.5) and update cadence (every 2 months vs every 5 months). Data Structure Display's advantage is ratings volume (676 vs 127) and review sentiment (62% vs 53%). On price, ads and iOS requirement 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. Data Structure Display sells 1 one-off in-app purchase. Codelet asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Codelet holds the better App Store score, 4.7 against 4.5. That said, the two scores are not equally well evidenced: Data Structure Display has 676 ratings behind it against 127, so its average is the more settled of the two. Written reviews complicate that: 62% of Data Structure Display's written reviews are positive against 53% of Codelet's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Data Structure Display ships an update every 5 months, Codelet every 2 months. The most recent releases landed on September 24, 2026 and August 13, 2026 respectively.

Scorecard7 real differences · 3 level
Data Structure Display versus Codelet: the parameters behind the verdict, then further details
ParameterData Structure DisplayCodelet
PriceFreeFree
Rating4.5 (676 ratings)4.7 (127 ratings) — better
Positive reviews61.9% of reviews — better53.3% of reviews
Number of ratings676 — better127
Update frequencyEvery 5 monthsEvery 2 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPod, Mac — betteriPhone, iPod
Requires iOS13.0 — better13.4
Further details — not scored
Size8 MB25 MB
Age rating4+4+
DeveloperJinan Matrix Information Technology Co., Ltd.Codelet LLC

Customer experience

Data Structure Display

All ratings676 ratings
Positive87.1%
Neutral2.4%
Negative10.5%
Written reviews42 reviews
Positive61.9%
Neutral2.4%
Negative35.7%

Codelet

All ratings126 ratings
Positive93.7%
Neutral3.2%
Negative3.2%
Written reviews15 reviews
Positive53.3%
Neutral20.0%
Negative26.7%

Bugs and requests

Data Structure Display

Reported bugs

2 issues
  • Aggressive review request frequency
  • Inconsistent dark mode functionality between iOS and macOS

Requested features

4 requests
  • Dark mode implementation
  • Comprehensive coverage of all data structure variants
  • More practical exercises and problems
  • Ad-supported free tier instead of paywall

Codelet

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Data Structure Display

One-time1
  • Unlock all data structures$2.99
None

Codelet

No in-app purchases

Questions

Is Data Structure Display free?
Data Structure Display is free to download, with in-app purchases available.
Is Codelet free?
Codelet is free to download, with no in-app purchases.
Which has better reviews, Data Structure Display or Codelet?
Codelet is rated higher. Data Structure Display averages 4.5 out of 5 from 676 ratings, while Codelet averages 4.7 from 127 ratings.
Do Data Structure Display or Codelet have ads?
Neither Data Structure Display nor Codelet shows ads.
Which is updated more often, Data Structure Display or Codelet?
Data Structure Display ships an update every 5 months, and Codelet every 2 months. Most recently, Data Structure Display was updated on September 24, 2026 and Codelet on August 13, 2026.

Other comparisons