66 Days vs Variance
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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/.
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.
- Probability practice
- Mental math exercises
- Logic puzzles
- Detailed solutions
- Progress tracking
- Topic-specific practice
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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
Verdict
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
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.
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.
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.
| Parameter | 66 Days | Variance |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (228 ratings) | 5.0 (5 ratings) — better |
| Positive reviews | 50.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 228 — better | 5 |
| Update frequency | Every 10 days — better | Every 2 weeks |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | Freemium |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 110 MB | 18 MB |
| Age rating | 4+ | 12+ |
| Developer | Uru Technologies, LLC | Benjamin Kawano |
Customer experience
66 Days
Variance
In-app purchases
66 Days
- 66 Days Prep Pro$15.991 Month
- 66 Days Prep Pro$49.991 Year
Variance
- Variance Pro Monthly7 Days trial$9.991 Month
- Variance Pro 6-Month$49.996 Months
- Variance Pro Yearly$99.991 Year









