Calibrex App vs MustDuo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Calibrex App
This wearable device precisely tracks your weightlifting reps, rest, and movements. It provides personalized insights into your training, offering live audio coaching and tailored workouts to help you achieve your strength, speed, or endurance goals.
- Precise rep, rest, and movement tracking
- Live audio coaching tailored to goals
- Personalized insights into training performance
- Advanced tracking and tailored workouts
- Set Score, Difficulty Score, Speed Score, Tempo Score
- Discover training trends and program balance
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Meet Calibrex — the wearable built for lifting. Calibrex is a tiny magnetic wearable that captures every rep, rest, and movement with unmatched precision — giving you deep, personalized insight into your training, and live audio coaching. Whether you're chasing strength, speed, or endurance, Calibrex adapts to your goals and pushes you further with intelligent feedback, advanced tracking, and tailored workouts that grow with you. Get coached through every set with live audio feedback — tailored to your goals, training style, and performance history. Set Score – How well you executed each rep and how intensely you pushed. Difficulty Score – How close you came to muscle failure. Speed Score – How closely your rep speed matched your target training zone. Tempo Score – How much time your muscles spent under tension. Discover powerful trends across your training — like increasing bench press volume, longer rest times, or missed muscle groups. Get a clearer picture of how balanced your program is across your entire body. 25M Reps & Counting. 1500 + professional weightlifters, coaches, university programs, and fitness enthusiasts across more than 15 countries.
MustDuo
This fitness app helps you build consistency and achieve your goals with real-time tracking and personalized plans. An AI coach provides guidance, motivation, and on-the-fly adjustments to keep you on track with your fitness journey.
- Smart workout tracking
- Personalized workout plans
- AI fitness coach
- Habit building features
- Gamified fitness experience
- Progress analytics
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MustDuo is your lifting partner that plans your fitness journey and adapts as you progress, helping you train smarter and reach your goals. Meet Naya, your personal coach and biggest cheerleader. She knows your goals, your plan and your recent training, so you can chat with her about your workouts, ask questions, or adjust your session when you need an easier day. Log each set with a tap, or pair the MustDuo Tracker to count reps for you. Watch your progress in charts, workout receipts and Apple Health. Whether you're new to lifting or chasing your next PR, MustDuo takes the guesswork out of training, makes every workout count, and helps you build a habit that lasts. YOUR PLAN, YOUR WEEK Choose your goal, experience level, and training schedule. MustDuo builds your personalized weekly plan and adapts it when life gets in the way. Swap exercises, shorten sessions, lighten a workout, or move it to another day with Naya. NAYA Your personal coach, right in your pocket. Ask questions, get training guidance, and adjust your workouts when life gets in the way. WORKOUTS Follow your personalized workout with pre-filled sets and reps, easy set tracking, and smart rest timers. Spend less time on your phone and more time focused on your lift. EXERCISE LIBRARY Explore 200+ exercises, most with HD demo videos, to help you learn proper form and train with confidence. PROGRESSIVE OVERLOAD, HANDLED Progressive overload made simple. MustDuo remembers your lifts and gradually adjusts your weights as you hit your targets, helping you consistently challenge yourself and get stronger. THE DASHBOARD See your strength, training volume, and consistency at a glance. Track trends over time and get clear insights on what to focus on next. YOUR WORKOUT RECEIPT See everything you accomplished: volume, reps, time, and a fun real-world comparison. Compare each workout to your previous session and share your progress. THE WINS TAB Build momentum with streaks, personal records and your workout receipts, and invite friends to train with you. Earn bananas and level up on your profile. THE MUSTDUO TRACKER, IN EARLY ACCESS Pair the MustDuo Tracker and it counts your reps, changes the weight and moves you through your workout without touching your phone. The tracker is in early access, and the app is fully functional without it. APPLE HEALTH Keep your fitness data connected. Sync your workouts with Apple Health and see your training alongside the rest of your activity. TRY IT FIRST Start a workout or plan your week from the first screen. Do 3 workouts as a guest before creating an account. Just lift. MustDuo handles the rest.
Screenshots
Verdict
The clearest difference is review sentiment: MustDuo at 100% against Calibrex App's 50%. MustDuo also leads on rating (5.0 vs 3.5). Calibrex App's advantage is device support (3 vs 1) and iOS requirement (15.1 vs 18.5). On price, ratings volume, 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. Neither carries in-app purchases, so what you see is what you pay.
MustDuo holds the better App Store score, 5.0 against 3.5. Both are backed by a comparable volume of ratings — 11 and 17 respectively. Written reviews point the same way: 50% of Calibrex App's written reviews are positive against 100% of MustDuo's.
Both ship on a similar rhythm, roughly fortnightly. Both last shipped on October 24, 2026.
| Parameter | Calibrex App | MustDuo |
|---|---|---|
| Price | Free | Free |
| Rating | 3.5 (11 ratings) | 5.0 (17 ratings) — better |
| Positive reviews | 50.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 11 | 17 — better |
| Update frequency | Fortnightly | Fortnightly |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.1 — better | 18.5 |
| Further details — not scored | ||
| Size | 150 MB | 59 MB |
| Age rating | 12+ | 12+ |
| Developer | CalibrexInc | MustDuo |
Customer experience
Calibrex App
MustDuo
In-app purchases
Calibrex App
No in-app purchases
MustDuo
No in-app purchases









