Challenge 4 Change vs ZoneFlow
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Challenge 4 Change
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PLEASE NOTE: YOU NEED A C4C ACCOUNT TO ACCESS THIS APP. IF YOU'RE A MEMBER GET IT FOR FREE AT YOUR GYM! Begin your journey to a healthier lifestyle and let C4C help you along the way. Introducing C4C, most comprehensive fitness platform with: Check class schedules and opening hours Track your daily fitness activities Track your weight and other body metrics Over 2000+ exercises and activities Clear 3D exercise demonstrations Preset workouts and the option to create your own Over 150 badges to earn Select workouts online and synchronize them with your app to workout at home or in the gym while keeping track of your progress. From strength to weight lifting, this app acts as your own personal trainer guiding and giving you the motivation you need. You can sync this app with Apple Health App. If you enable this connection, any workout in the Health app with automatically be added to your Activity Calendar.
ZoneFlow
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ZoneFlow: Effortless Heart Rate Training Stay in your optimal performance zone without constant screen checking. ZoneFlow is the ultimate minimalist training companion for runners who want to train smarter, not harder. Why ZoneFlow? Silent Zone Guidance Haptic feedback keeps you precisely in your target heart rate zone No more constant screen glances - run with pure focus Advanced algorithms track your heart rate in real-time Intelligent Training Custom heart rate zone setup for personalized training Works seamlessly with Apple Watch Supports all fitness levels, from beginners to elite athletes Key Features Customizable heart rate zones Minimal, distraction-free interface Accurate heart rate monitoring Instant haptic alerts when you drift from your zone Perfect for: Marathon trainers Endurance athletes Fitness runners seeking precision Train smarter. Run free. Run with ZoneFlow.
Screenshots
Verdict
The clearest difference is update cadence: Challenge 4 Change at every 3 months against ZoneFlow's every 18 months. ZoneFlow's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support 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.
Challenge 4 Change ships an update every 3 months, ZoneFlow every 18 months. The most recent releases landed on September 8, 2026 and May 31, 2026 respectively.
| Parameter | Challenge 4 Change | ZoneFlow |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 3 months — better | Every 18 months |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPod | iPhone, iPod, Apple Watch — better |
| Requires iOS | 15.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 213 MB | 2 MB |
| Age rating | 12+ | 4+ |
| Developer | Challenge 4 Change GmbH | Adrian Rollett |
In-app purchases
Challenge 4 Change
No in-app purchases
ZoneFlow
No in-app purchases





