Comparison

CodeNexus vs Big O Notation

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

Head to head
About

CodeNexus

Master coding interviews with focused learning paths and real-world problems. Prepare strategically anytime, anywhere, without subscriptions. Built for results, it helps you gain an edge in tech interviews.

Highlights
  • Master data structures and algorithms
  • Solve real-world interview problems
  • Focused learning paths
  • Distraction-free coding experience
  • Pattern recognition focus
  • Multiple difficulty levels
Features
Read full description

CodeNexus | Your Coding Interview Edge Stop scrolling mindlessly. Start preparing strategically. Turn dead time into progress. STUDY ANYWHERE On the toilet. On the couch. At your desk. Even in line. CodeNexus is a modern coding interview prep app designed to help you master data structures, algorithms, and real interview problems anytime, anywhere. WHY CODENEXUS? Most platforms are bloated, expensive, and frustrating. CodeNexus is different: No subscriptions — pay once, own your prep Focused learning paths — no noise, just what matters Built for real interviews — not just theory WHAT YOU’LL LEARN Master the topics that actually get asked: Arrays & Strings Hash Maps & Sets Sliding Window Two Pointers Stacks & Queues Trees & Graphs Recursion & Backtracking Dynamic Programming PRACTICE LIKE A REAL INTERVIEW Real-world, LeetCode-style problems Multiple difficulty levels (Easy to Hard) Clean, distraction-free coding experience Built to simulate real interview thinking LEARN FASTER (NOT HARDER) Clear, structured explanations Breakdowns that actually make sense Focus on pattern recognition (what interviewers test) BUILT FOR RESULTS Whether you're: Preparing for FAANG / Big Tech Switching into software engineering Leveling up your problem-solving skills CodeNexus helps you get there faster. YOUR EDGE STARTS HERE Download CodeNexus and take control of your interview prep. Own your preparation. Own your outcome.

About

Big O Notation

Features
Read full description

Big O Notation is an independent study app for learning, reviewing, and practicing algorithm complexity. It is built for students, self-taught developers, coding interview candidates, and anyone who wants clearer intuition for time and space complexity. Study across Fundamentals, Practical Skills, Common Pitfalls, and Advanced Concepts with 160 focused questions. Every question includes an explanation so you can understand why an answer is right and where your reasoning went off track. Features: - FSRS spaced-repetition intervals for smarter review - Weak-point heatmap to spot topics that need attention - Daily challenge for steady practice - Mock exams for timed review - Offline practice - No login required Practice offline, no login required. Independent study app for Big O Notation practice. Not affiliated with, endorsed by, or sponsored by any company, certification body, exam operator, or vendor. All trademarks belong to their respective owners.

Screenshots

CodeNexus4 screens
Big O Notation4 screens

Verdict

The call

The clearest difference is in-app purchases: Big O Notation at none against CodeNexus's 1. Big O Notation also leads on iOS requirement (15.1 vs 18.0). On price, 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

Both are free to download. CodeNexus sells 1 one-off in-app purchase. Big O Notation asks for nothing beyond the download.

Scorecard2 real differences · 7 level
CodeNexus versus Big O Notation: the parameters behind the verdict, then further details
ParameterCodeNexusBig O Notation
PriceFreeFree
Rating5.0 (3 ratings) — better—
Number of ratings3 — better—
Update frequencyEvery 4 days—
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.015.1 — better
Further details — not scored
Size48 MB38 MB
Age rating9+4+
DeveloperJordan SchillingAFTW LLC

In-app purchases

1 purchases

CodeNexus

One-time1
  • Lifetime Unlock$14.99
None

Big O Notation

No in-app purchases

Questions

Is CodeNexus free?
CodeNexus is free to download, with in-app purchases available.
Is Big O Notation free?
Big O Notation is free to download, with no in-app purchases.
Do CodeNexus or Big O Notation have ads?
Neither CodeNexus nor Big O Notation shows ads.

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