Comparison

66 Days vs Variance

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

Head to head
About

66 Days

Master banking and consulting interviews with daily AI-powered practice. Track your progress on a 66-day journey with personalized feedback on technical, behavioral, and case questions. Improve your resume and gain confidence for top firms.

Highlights
  • AI interview coach with personalized feedback
  • Daily drills for behavioral, technical, and case questions
  • 66-day progress heat map
  • Resume checker
  • Excel and valuation tools
  • Analytics dashboard
Features
Read full description

66 Days Prep is an AI-powered career preparation platform designed to help candidates master interviews for banking and consulting roles through structured, daily progress. The app combines personalized coaching, habit tracking, and analytics to transform your preparation into a consistent 66-day journey. Each day you’ll train across behavioral, technical, cases or market-based questions while receiving instant feedback from an AI coach. The goal is simple — make interview mastery a daily habit. Your progress is visualized through a 66-day heat map that tracks consistency, focus, and improvement. Every session compounds your learning so that when interview season arrives, you’re confident, sharp, and ready to perform. Key features: • AI interview coach for personalized feedback on real questions • Daily drills in behavioral, technical, cases, and market news • 66-day heat map that tracks performance and consistency • Resume checker to strengthen clarity and impact • Excel and valuation tools for technical accuracy • Productivity features including timers and streak reminders • Analytics dashboard that highlights your growth over time Built by former bankers and consultants, 66 Days Prep mirrors real recruiting standards at leading firms such as Goldman Sachs, Morgan Stanley, McKinsey, and Bain. The app ensures that every minute spent practicing is focused on what matters most — structured thinking, confident delivery, and business intuition. Whether you are recruiting for your first internship, preparing for post-graduate consulting interviews, or advancing your career in finance, 66 Days Prep provides a disciplined path to daily improvement. Consistency is what separates good candidates from great ones. 66 Days Prep helps you build that consistency through smart repetition, clear feedback, and visible progress you can track. Build momentum, develop confidence, and master your interviews with 66 Days Prep — your AI career partner for banking and consulting success. Some features, including the AI interview coach, require a subscription. Please review our Privacy Policy at https://www.66daysprep.com/privacy. By using this app, you agree to the terms outlined in https://www.66daysprep.com/terms and https://www.apple.com/legal/internet-services/itunes/dev/stdeula/.

About

Variance

Prepare for quantitative finance interviews with this app. Practice probability, mental math, logic puzzles, and more with detailed solutions and progress tracking. Sharpen your mathematical intuition and problem-solving skills for trading and research roles.

Highlights
  • Probability practice
  • Mental math exercises
  • Logic puzzles
  • Detailed solutions
  • Progress tracking
  • Topic-specific practice
Read full description

Variance is the ultimate quant interview prep app for aspiring traders, quant researchers, and finance professionals. Whether you're targeting a role at a hedge fund, trading firm, or just prepping for fun, Variance gives you the tools to practice the quantitative skills that top firms test — rigorously and on the go. WHAT YOU'LL PRACTICE • Probability • Mental math • Sequences & Patterns • Brainteasers & logic puzzles • Expected value FEATURES • Hundreds of problems across multiple difficulty levels • Detailed solutions and explanations for every question • Topic-by-topic practice to target your weak spots • Progress tracking to see how you improve over time • Clean, distraction-free interface built for focused study WHO IT'S FOR Variance is built for students and professionals preparing for quantitative interviews at top firms, and other top quant shops. It's also great for anyone who wants to sharpen their mathematical intuition and problem-solving speed. Prepare smarter. Interview with confidence. Download Variance today. Terms of Use: www.thequantprepapp.com/terms Privacy Policy: www.thequantprepapp.com/privacy

Screenshots

66 Days4 screens
Variance4 screens

Verdict

The call

66 Days and Variance both sit at 4.9 stars, but that hides the real split: 100% of Variance's written reviews are positive against 50% of 66 Days's. 66 Days's advantage is ratings volume (228 vs 5) and iOS requirement (17.0 vs 26.0). On price, rating, update cadence and 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

Both are free to download. 66 Days sells 2 in-app purchases, starting at $15.99 per month and Variance sells 3 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.9 for 66 Days against 5.0 for Variance. That said, the two scores are not equally well evidenced: 66 Days has 228 ratings behind it against 5, so its average is the more settled of the two. Written reviews are what separate them: 50% of 66 Days's written reviews are positive against 100% of Variance's.

UpkeepUpdate frequency

66 Days ships an update every 10 days, Variance every 2 weeks. The most recent releases landed on October 7, 2026 and October 15, 2026 respectively.

Scorecard3 real differences · 7 level
66 Days versus Variance: the parameters behind the verdict, then further details
Parameter66 DaysVariance
PriceFreeFree
Rating4.9 (228 ratings)5.0 (5 ratings) — better
Positive reviews50.0% of reviews100.0% of reviews — better
Number of ratings228 — better5
Update frequencyEvery 10 days — betterEvery 2 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFreemiumFreemium
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better26.0
Further details — not scored
Size110 MB18 MB
Age rating4+12+
DeveloperUru Technologies, LLCBenjamin Kawano

Customer experience

66 Days

All ratings228 ratings
Positive96.9%
Neutral1.3%
Negative1.8%
Written reviews6 reviews
Positive50.0%
Neutral16.7%
Negative33.3%

Variance

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

2 purchases

66 Days

Subscriptions2
  • 66 Days Prep Pro$15.991 Month
  • 66 Days Prep Pro$49.991 Year
3 purchases

Variance

Subscriptions3
  • Variance Pro Monthly7 Days trial$9.991 Month
  • Variance Pro 6-Month$49.996 Months
  • Variance Pro Yearly$99.991 Year

Questions

Is 66 Days free?
66 Days is free to download, with in-app purchases available.
Is Variance free?
Variance is free to download, with in-app purchases available.
Which has better reviews, 66 Days or Variance?
Variance is rated higher. 66 Days averages 4.9 out of 5 from 228 ratings, while Variance averages 5.0 from 5 ratings.
Do 66 Days or Variance have ads?
Neither 66 Days nor Variance shows ads.
Which is updated more often, 66 Days or Variance?
66 Days ships an update every 10 days, and Variance every 2 weeks. Most recently, 66 Days was updated on October 7, 2026 and Variance on October 15, 2026.

Other comparisons