Comparison

Data Structure Display vs Fab Gap

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

Fab Gap

Features
Read full description

$52 billion in government investment. $500 billion in private commitments. 90% of the world's most advanced chips made in Taiwan — 110 miles from mainland China. This is not a technology story. This is the foundation of every industry in America — and it is being rebuilt right now. Fab Gap is a free educational app that explains America's semiconductor buildout in plain language. Built by a 15-year Intel physical design engineer with hands-on tapeout experience, it gives business leaders, policymakers, and executives the knowledge they need to understand and act on the largest industrial shift in a generation. WHAT YOU'LL LEARN Module 00 · Why This Matters The real numbers. The real stakes. Why every business — not just technology companies — must understand the semiconductor shift happening right now. Module 01 · The Stack How a chip is physically built — from silicon wafer to finished die. Layer by layer, in plain language. Module 02 · Process Nodes From 180nm legacy chips to Intel 18A cutting edge. What the node numbers mean, what they cost, and why they matter for American competitiveness. Module 03 · Physical Design & Verification DRC, LVS, ERC, timing corners, waveform verification — the checklist between a chip design and working silicon. Module 04 · Design Flow Schematic to tapeout. The full journey a chip takes from idea to manufactured reality. Module 05 · The Ecosystem Who designs chips, who manufactures them, and why the gap between Taiwan and America defines global power. Module 06 · CHIPS Act Where the $52 billion goes, who received it, what is being built, and what the current challenges are. Module 07 · AI & Advanced Packaging Why AI accelerators are driving the push to advanced nodes — and why packaging now matters as much as the node itself. Module 08 · Who Benefits & How Construction, software, EDA, equipment, staffing, services, and certified small businesses — every industry has a CHIPS Act opportunity. Module 09 · Industry Players The full semiconductor value chain by tier — from TSMC and Intel to Cadence, Synopsys, and the emerging firms building the next layer of the ecosystem. WHO THIS IS FOR · Business leaders evaluating CHIPS Act opportunities · Congressional staff and policy advisors · C-suite executives navigating semiconductor supply chain decisions · Government contracting officers and procurement professionals · Investors and analysts covering the chip industry · Entrepreneurs and small business owners seeking certified pathways · Anyone who wants to understand the industry driving AI, defense, and the modern economy BUILT BY Fab Gap was built by the founder of Souletics Software — a 15-year Intel physical design engineer with hands-on experience in custom layout and cryptography chip tapeouts, an AI Cloud Solutions Architect at Intel's Office of the CTO, and a HUBZone-certified small business owner supporting America's domestic semiconductor buildout. Free. No subscription. No login. No ads.

Screenshots

Data Structure Display4 screens
Fab Gap4 screens

Verdict

The call

The clearest difference is price: Data Structure Display at Free against Fab Gap's $19.99. Data Structure Display also leads on device support (4 vs 2) and iOS requirement (13.0 vs 17.6). Fab Gap's advantage is in-app purchases (none vs 1) and update cadence (daily vs every 5 months). On ads 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

Data Structure Display is free to download; Fab Gap costs $19.99 up front. Data Structure Display sells 1 one-off in-app purchase. Fab Gap asks for nothing beyond the download.

UpkeepUpdate frequency

Data Structure Display ships an update every 5 months, Fab Gap daily. The most recent releases landed on October 13, 2026 and October 7, 2026 respectively.

Scorecard5 real differences · 5 level
Data Structure Display versus Fab Gap: the parameters behind the verdict, then further details
ParameterData Structure DisplayFab Gap
PriceFree — better$19.99
Rating4.5 (676 ratings) — better—
Positive reviews61.9% of reviews—
Number of ratings676 — better—
Update frequencyEvery 5 monthsDaily — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod, Mac — betteriPhone, iPad
Requires iOS13.0 — better17.6
Further details — not scored
Size8 MB1 MB
Age rating4+4+
DeveloperJinan Matrix Information Technology Co., Ltd.Souletics, LLC

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

Fab Gap

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

Fab Gap

No in-app purchases

Questions

Is Data Structure Display free?
Data Structure Display is free to download, with in-app purchases available.
Is Fab Gap free?
Fab Gap costs $19.99, with no in-app purchases.
Do Data Structure Display or Fab Gap have ads?
Neither Data Structure Display nor Fab Gap shows ads.
Which is updated more often, Data Structure Display or Fab Gap?
Data Structure Display ships an update every 5 months, and Fab Gap daily. Most recently, Data Structure Display was updated on October 13, 2026 and Fab Gap on October 7, 2026.

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