Zetamac Arithmetic Practice vs 66 Days
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Zetamac Arithmetic Practice
This app offers mental math practice tailored for quantitative finance professionals. It focuses on improving calculation speed and accuracy for complex numerical problems.
- Mental math practice
- Quantitative finance focus
- Calculation speed improvement
- Accuracy enhancement
- Numerical problem solving
Read full descriptionHide full description
Zetamac - A mental math practice app used in the Quantitative Finance world.
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
Read full descriptionHide 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/.
Screenshots
Verdict
The clearest difference is in-app purchases: Zetamac Arithmetic Practice at none against 66 Days's 2. Zetamac Arithmetic Practice also leads on review sentiment (82% vs 50%) and update cadence (daily vs every 10 days). 66 Days's advantage is rating (4.9 vs 4.7) and ratings volume (228 vs 18). 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
Both are free to download. 66 Days sells 2 in-app purchases, starting at $15.99 per month. Zetamac Arithmetic Practice asks for nothing beyond the download.
66 Days holds the better App Store score, 4.9 against 4.7. That said, the two scores are not equally well evidenced: 66 Days has 228 ratings behind it against 18, so its average is the more settled of the two. Written reviews complicate that: 82% of Zetamac Arithmetic Practice's written reviews are positive against 50% of 66 Days's, so the app with the better star average is not the one people write more warmly about.
Zetamac Arithmetic Practice ships an update daily, 66 Days every 10 days. The most recent releases landed on September 22, 2026 and September 14, 2026 respectively.
| Parameter | Zetamac Arithmetic Practice | 66 Days |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (18 ratings) | 4.9 (228 ratings) — better |
| Positive reviews | 82.4% of reviews — better | 50.0% of reviews |
| Number of ratings | 18 | 228 — better |
| Update frequency | Daily — better | Every 10 days |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Freemium |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.5 | 17.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 110 MB |
| Age rating | 4+ | 4+ |
| Developer | Joseph Ma | Uru Technologies, LLC |
Customer experience
Zetamac Arithmetic Practice
66 Days
In-app purchases
Zetamac Arithmetic Practice
No in-app purchases
66 Days
- 66 Days Prep Pro$15.991 Month
- 66 Days Prep Pro$49.991 Year
Questions
Is Zetamac Arithmetic Practice free?
Is 66 Days free?
Which has better reviews, Zetamac Arithmetic Practice or 66 Days?
Do Zetamac Arithmetic Practice or 66 Days have ads?
Which is updated more often, Zetamac Arithmetic Practice or 66 Days?
Other comparisons
