Comparison

Built By Karl vs Biomtrx

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

Head to head
About

Built By Karl

Features
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Built By Karl is a fitness and lifestyle coaching app designed to help busy men build strength, lose body fat, and create sustainable habits alongside work and family life. The app provides structured training programs, simple nutrition guidance, and daily accountability tools to support long-term consistency. Users can follow workouts tailored to their goals, track progress over time, and stay organised with habit tracking and check-ins. Key features include: Personalised workout plans with exercise demonstrations Progress tracking for workouts, body metrics, and habits Nutrition guidance and food tracking support In-app messaging for communication and feedback Goal setting and reminders to support consistency Built By Karl focuses on practical routines that fit around real life, helping users stay consistent without extreme diets or complicated systems. Everything is delivered in one place to make fitness simple, structured, and manageable. *App access requires a paid coaching plan. Terms Of Use: https://kahunas.io/terms-conditions Privacy Policy: https://kahunas.io/privacy Medical Disclaimer: This app does not provide medical advice, diagnoses, or treatment. The information and guidance provided within the app are for general fitness and wellbeing purposes only. Always seek the advice of your physician or other qualified healthcare provider before starting any exercise program, changing your nutrition, or making decisions regarding your health.

About

Biomtrx

Features
Read full description

Biomtrx is a free utility that connects Apple Health on your iPhone to your existing Kahunas coaching account, saving you from entering health metrics manually. Share the health data you choose so your coach has useful context when reviewing your training, nutrition and recovery. HOW IT WORKS Sign in with the account you use with your coach. Read the explanation for each data type, then choose what to allow on Apple's own permission screen. Biomtrx securely sends available, approved records to your Kahunas coaching environment and shows your connection and sync status. You and your coach use the data in Kahunas alongside your coaching programme. WHAT YOU CAN SHARE Every data type is optional and depends on what your devices or apps have recorded in Apple Health. Activity: steps, walking/running distance, cycling distance, swimming distance, downhill snow-sport distance, flights climbed and recorded workouts help your coach review movement and activity volume. Walking speed, cycling cadence and cycling power provide additional context for walking or cycling sessions. Wheelchair push counts let wheelchair users share a relevant movement measure. Training and recovery: heart rate, resting heart rate, heart-rate variability (SDNN), sleep times and available sleep stages give your coach context to consider alongside your own feedback. Recorded respiratory rate and body temperature are optional additional context. VO2 max estimates can help your coach review aerobic-fitness trends. Body measurements and energy: weight and height provide body-measurement context. Active energy and basal energy are the activity and resting-energy estimates already recorded in Apple Health, which your coach can consider when reviewing training and nutrition goals. Hydration: water intake already logged in Apple Health can be shared without entering it again in your coaching platform. Biomtrx does not read food diaries or dietary calorie intake. YOU CONTROL ACCESS Biomtrx reads only the Apple Health data you allow. You can decline individual types and continue using the app. Biomtrx does not write to Apple Health. Syncing can run in the background when iOS allows it. Your phone controls timing, so background updates are not guaranteed at a fixed interval. Open Biomtrx and tap Sync now to check for new records. Turn off access in Apple Health or sign out of Biomtrx to stop new reads. Signing out does not delete records already sent to your coach. To delete your account and that data, use Delete my account in the app, or contact your coach. Biomtrx contains no advertising and does not sell your health data or use it for tracking or advertising. Approved records are sent to your Kahunas coaching environment for your coaching programme. Biomtrx displays sync status; your health readings and coaching programme are viewed in Kahunas. Any independent coach, personal trainer, yoga instructor, gym or studio can sign up at Kahunas.io. To use Biomtrx, you need a Kahunas client account through an invitation from your coach, gym or studio. Biomtrx does not create standalone accounts and has no paid features or in-app purchases. Biomtrx is a fitness and wellness companion, not a medical device. It does not diagnose conditions, provide medical advice, monitor illness, predict fertility or generate health or recovery scores.

Screenshots

Built By Karl3 screens
Biomtrx4 screens

Verdict

The call

The clearest difference is in-app purchases: Biomtrx at none against Built By Karl's 1. Biomtrx also leads on update cadence (every 9 days vs every 3 months). Built By Karl's advantage is device support (3 vs 1). On price, ads and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Built By Karl sells 1 in-app purchase, starting at $299.99 per month. Biomtrx asks for nothing beyond the download.

UpkeepUpdate frequency

Built By Karl ships an update every 3 months, Biomtrx every 9 days. The most recent releases landed on November 5, 2026 and November 6, 2026 respectively.

Scorecard3 real differences ยท 3 level
Built By Karl versus Biomtrx: the parameters behind the verdict, then further details
ParameterBuilt By KarlBiomtrx
PriceFreeFree
Update frequencyEvery 3 monthsEvery 9 days โ€” better
AdsNoNo
In-app purchasesYesNo โ€” better
DevicesiPhone, iPad, iPod โ€” betteriPhone
Requires iOS15.0 โ€” better16.4
Further details โ€” not scored
Size56 MB46 MB
Age rating17+4+
DeveloperKarl JardinecoFox Digital Ltd.

In-app purchases

1 purchases

Built By Karl

Subscriptions1
  • Monthly 1-1$299.991 Month
None

Biomtrx

No in-app purchases

Questions

Is Built By Karl free?
Built By Karl is free to download, with in-app purchases available.
Is Biomtrx free?
Biomtrx is free to download, with no in-app purchases.
Do Built By Karl or Biomtrx have ads?
Neither Built By Karl nor Biomtrx shows ads.
Which is updated more often, Built By Karl or Biomtrx?
Built By Karl ships an update every 3 months, and Biomtrx every 9 days. Most recently, Built By Karl was updated on November 5, 2026 and Biomtrx on November 6, 2026.

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