Comparison

Learn Kotlin vs Big O Notation

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

Head to head
About

Learn Kotlin

Features
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Learn Kotlin from scratch โ€” no experience needed. Bite-sized Kotlin lessons, a real code editor on your phone, and an AI mentor that answers your questions in seconds. Built for complete beginners, students and career switchers. WHY LEARN Kotlin? โ€ข Kotlin is an in-demand skill โ€” a strong addition to any resume โ€ข Learn by doing: every lesson mixes short theory with hands-on practice โ€ข Build real foundations you can use in projects, work and interviews โ€ข Start from zero โ€” every concept is explained in plain language WHAT YOU'LL LEARN โ€ข Kotlin fundamentals โ€” the core concepts, step by step โ€ข The essential building blocks used in real-world Kotlin work โ€ข Practical techniques you can apply right away โ€ข Common mistakes โ€” and how to avoid them โ€ข Hands-on exercises after every topic โ€ข Advanced topics to keep growing beyond the basics EVERYTHING YOU NEED TO LEARN Kotlin โ€ข AI Mentor โ€” stuck on a concept or an error? Ask anything and get a clear answer in seconds โ€ข 100+ bite-sized lessons (5โ€“10 minutes each) โ€” built for real life, not lecture halls โ€ข Real code editor โ€” write and run Kotlin code right on your phone โ€ข Quizzes and coding challenges after every topic to lock in what you learn โ€ข Weekly Code Challenge โ€” compete with learners around the world โ€ข Certificate of completion โ€” pass the final exam and prove your skills โ€ข Streaks, progress tracking and smart reminders to keep you consistent โ€ข Learn on the go โ€” lessons load fast and keep working on flaky connections โ€ข App available in 22 languages WHO IT'S FOR โ€ข Complete beginners taking their first steps โ€ข Students who want extra practice alongside classes โ€ข Career switchers building job-ready skills โ€ข Anyone curious about Kotlin Part of CoddyKit โ€” a family of 40+ coding apps trusted by 100,000+ learners worldwide. Free to start: your first course is free, with a daily AI Mentor allowance. Pro unlocks every course, removes ads and gives you unlimited AI Mentor. Download Learn Kotlin: Code & Build and write your first line of Kotlin today. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.coddykit.com/terms/privacy-policy

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

Learn Kotlin4 screens
Big O Notation4 screens

Verdict

The call

The clearest difference is in-app purchases: Big O Notation at none against Learn Kotlin's 4. Big O Notation also leads on ads (none vs shown). On price, device support and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Learn Kotlin sells 4 in-app purchases, starting at $4.99 per 7 days. Big O Notation asks for nothing beyond the download.

Scorecard2 real differences ยท 4 level
Learn Kotlin versus Big O Notation: the parameters behind the verdict, then further details
ParameterLearn KotlinBig O Notation
PriceFreeFree
Update frequencyEvery 3 weeksโ€”
AdsYesNo โ€” better
In-app purchasesYesNo โ€” better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.115.1
Further details โ€” not scored
Size71 MB38 MB
Age rating4+4+
DeveloperMEHMET CANKER (TR)AFTW LLC

In-app purchases

4 purchases

Learn Kotlin

Subscriptions3
  • Weekly Subscription$4.997 Days
  • Monthly Subscription$6.991 Month
  • Yearly Subscription$24.991 Year
One-time1
  • Lifetime Subscription$59.99
None

Big O Notation

No in-app purchases

Questions

Is Learn Kotlin free?
Learn Kotlin 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 Learn Kotlin or Big O Notation have ads?
Learn Kotlin shows ads; Big O Notation does not.

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