Train with a compatible Bluetooth chest strap: live zones, Lock Screen Live Activity, audio and vibration alerts, structured workouts, history and TCX export.
Train in your heart rate zones using your Bluetooth chest strap — no smartwatch required.
Strap Zone connects directly to your heart rate monitor and shows real-time zone data on your iPhone. Use it for zone 2 sessions, HIIT, intervals, or other heart-rate-based training.
WHY CHEST STRAP + PHONE?
Chest straps provide reliable heart-rate data during workouts and are often more responsive than wrist-based monitors. Most zone training apps require an Apple Watch. Strap Zone doesn't. Just your phone and your strap.
FEATURES
Real-Time HR Zones (Z1–Z5)
See your current zone with bold, color-coded display:
Z1 Recovery | Z2 Endurance | Z3 Tempo | Z4 Threshold | Z5 VO2 Max
Zone 2 Training Made Simple
Use zone 2 sessions to organise steady aerobic training. Audio alerts tell you when your measured heart rate leaves the target zone, so you do not need to watch the screen.
Structured Workouts
Build custom interval workouts with target zones, repeat blocks, and timed segments. Perfect for HIIT, threshold training, or guided zone 2 sessions.
Time-in-Zone Tracking
See exactly how long you spent in each zone during and after your workout.
Workout History
Review past sessions with detailed zone breakdowns and heart rate data.
Optional Apple Health Export
Off by default. If you opt in, Strap Zone can write your completed workouts and the recorded data you select to Apple Health: heart rate, estimated active energy, distance and GPS route, when system permissions allow. Strap Zone never imports health data from other apps.
Optional GPS + TCX Export
Record route, distance, pace splits, and export a complete TCX file for platforms like Strava, Garmin Connect, and TrainingPeaks. GPS can be turned off anytime in Settings.
Large, Clear Display
Big BPM numbers easy to read during any workout — on the treadmill, bike, or gym floor.
COMPATIBLE BLUETOOTH HEART RATE SENSORS
Strap Zone is designed for sensors that broadcast the standard Bluetooth Low Energy Heart Rate Service. Compatibility is model-specific. Our public evidence matrix documents the current status for Polar H10, Garmin HRM-Dual, Wahoo TICKR and other named models:
https://strapzone.app/compatible-heart-rate-monitors/
Compatible watches may also connect when they broadcast the same service. Availability varies by model.
SIMPLE BY DESIGN
Optional GPS when you want route export. No account. Just heart rate zones — done right.
Your heart rate and GPS route data stay on your device unless you explicitly enable an export. No account.
Works on iPhone, iPad (with Split Screen support), and Mac with Apple Silicon.
Terms of Service: https://strapzone.app/terms/
This app is highly configurable and meets all of the requirements I had in mind, plus it has many more features that hadn’t occurred to me. I’ve been using it with a Garmin HRM 200 and it’s been working flawlessly. The support is excellent and very responsive. I van’t say enough good things about it.
Awesome
Etan1984
Simple and highly effective, necessary data without excess noise.
Stopped working
DougArcane
I had used the free version for a month or so and I liked it enough to buy it. It no longer connects to Bluetooth and thinks Bluetooth is not enabled, even though all my other Bluetooth devices work just fine. So now completely useless to me.PS tried all the usual, downloading again, rebooting iphone etc.
Developer Response
Hey, thanks for reporting the issue. Fix is already live. Sorry for the hassle.
Free
Andrew Silverfine
Works great. All you need to monitor your heart rate for free!
Workout times in History are right again. After you close and reopen Strap Zone, start times now stay in your local time. Your recorded workouts were never changed.
Version 3.21.19
The developer, Wojciech Zieba, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
Health & Fitness
Purchases
Location
Identifiers
Usage Data
Diagnostics
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Wojciech Zieba
Size
79.6 MB
Category
Sports
Compatibility
Requires iOS 16.0 or later.
iPhone Requires iOS 16.0 or later.
iPad Requires iPadOS 16.0 or later.
Mac Requires macOS 13.0 or later and a Mac with Apple M1 chip or later.
Location
This app may use your location even when it isn’t open, which can decrease device battery life.