Comparison

Cogni vs Cardstack Study

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

Head to head
About

Cogni

Create and study flashcards using an AI-enhanced spaced repetition algorithm to optimize learning. Access a vast library of pre-made decks and track your progress with detailed statistics. Study offline with media-supported flashcards.

Highlights
  • AI-enhanced spaced repetition
  • Create and review flashcards
  • Library of pre-made decks
  • Detailed statistics and progress tracking
  • Offline access with media support
  • Customizable flashcard creation
Read full description

Cogni empowers you to master new materials effortlessly by creating and studying flashcards. Built on an enhanced spaced repetition algorithm, the app optimizes your study sessions, ensuring you get the most out of your learning. Whether preparing for exams, studying languages, or mastering complex subjects, millions trust flashcards to achieve their goals. Start your journey to mastery today—no limits, no boundaries, just learning! - Languages - Medicine (MCAT, USMLE & More) - Anatomy & Physiology - Exam preparation (SAT, GRE & More) - Math - Law - Geography - Computing - And many more! Key Benefits: - Easily create and review flashcards tailored to your learning needs. - Customize your cards with colors, lists, and more to fit your style. - Access a massive library of pre-made decks to jumpstart your learning. - Review lecture materials and prep for exams with powerful spaced repetition. Thousands of students boost their grades with this science-backed approach. - AI-enhanced spaced repetition (SRS) for optimal recall. - Flexible study interface with swipe and tap actions for efficient learning. - Detailed statistics and progress tracking to monitor your success. - Offline access to study with media-supported flashcards. Get started with Cogni today and take control of your learning journey! Terms of Use: https://cogni.cards/terms/ Privacy Policy: https://cogni.cards/privacy/

About

Cardstack Study

Features
Read full description

Cardstack is a flashcard app for memorising things properly, languages, dates, definitions, exam material, anything you need to actually know rather than vaguely recognise. You organise cards into subjects and stacks, then study them in three escalating modes: Absorb to read through with no pressure, Practice to type your answers with mistakes forgiven, and Test to prove you know them cold. Cards you get right drop away; cards you get wrong keep coming back until they don't. Anything you master returns days or weeks later, so it stays learned. Most flashcard apps let you feel productive without learning anything. Cardstack is built so you can't do that. It won't call you finished until you actually are. HOW IT WORKS Absorb — cards flip automatically, no pressure, just read and take it in. Practice — type your answers. Three correct in a row masters a card. Typos are forgiven. Test — the strict version. Three correct, no typos forgiven. Any mistake resets the card to zero. WHY IT WORKS Most revision rewards recognition, not recall. You see an answer, think "yes, obviously," and move on having learned almost nothing, until it matters and it's gone. Cardstack is built around active recall instead: actually retrieving something from memory, not just recognising it. You can't mark yourself correct. The card decides. Once a stack is mastered, it comes back on a schedule, 3 days, then 7, then 14, then 30, so what you've learned stays learned instead of fading by morning. WHO IT'S FOR Students revising for GCSEs, A-levels or finals. Professionals studying for licensing exams. Career-changers picking up new terminology. Language learners building real vocabulary. Anyone who's ever sworn they knew something, right up until they needed it. Free to download.

Screenshots

Cogni4 screens
Cardstack Study4 screens

Verdict

The call

The clearest difference is in-app purchases: Cardstack Study at none against Cogni's 9. On price, ads, device support 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. Cogni sells 9 in-app purchases, starting at $4.99 per month. Cardstack Study asks for nothing beyond the download.

Scorecard1 real difference · 9 level
Cogni versus Cardstack Study: the parameters behind the verdict, then further details
ParameterCogniCardstack Study
PriceFreeFree
Rating4.7 (1.7K ratings) — better—
Positive reviews35.7% of reviews—
Number of ratings1.7K — better—
Update frequencyEvery 9 days—
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPadiPhone, iPod
Requires iOS16.415.1 — better
Further details — not scored
Size69 MB33 MB
Age rating4+4+
DeveloperCOGNIFLY LTDAngus Gibson

Bugs and requests

Cogni

Reported bugs

2 issues
  • App no longer available after paying for annual subscription
  • Occasional crashes

Requested features

4 requests
  • Integrate ChatGPT or Claude for automatic card creation
  • Add sub-decks for larger decks that need more review
  • Improve algorithm for hard/again ratings to better target struggling cards
  • Add subsections for decks to study different sections separately

Cardstack Study

Not enough reviews yet to summarise bugs or requests.

In-app purchases

9 purchases

Cogni

Subscriptions7
  • Premium Monthly$4.991 Month
  • Premium Monthly$7.991 Month
  • Premium Monthly$14.991 Month
Show 4 more
  • Premium Annual$19.991 Year
  • Premium Annual$24.991 Year
  • Premium Annual$29.991 Year
  • Premium Annual$49.991 Year
One-time2
  • Lifetime Premium$69.99
  • Premium Lifetime$99.99
None

Cardstack Study

No in-app purchases

Questions

Is Cogni free?
Cogni is free to download, with in-app purchases available.
Is Cardstack Study free?
Cardstack Study is free to download, with no in-app purchases.
Do Cogni or Cardstack Study have ads?
Neither Cogni nor Cardstack Study shows ads.

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