Heart Alert connects to your Bluetooth heart rate chest strap, armband or watch and plays a sound the moment your BPM goes above or below the range you set. Choose a minimum and a maximum, put your phone away, and train by ear.

No screen-watching. No zone math. No account.

How it works

1. Put on your chest strap or armband, or turn on heart rate broadcast on your watch. 2. Set your min and max BPM. 3. Press start — you get an alert when you drift too high or too low, and another one when you are back in range.

Features

– Custom minimum and maximum BPM limits – High heart rate alerts and low heart rate alerts – Immediate audio alerts, with adjustable volume – Optional vibration – Repeat interval of 1, 3, 5 or 10 seconds while you are out of range – "Out of range for" delay, so a short spike or a passing dip stays quiet – Initial delay, to keep things silent during your warm-up – Sensor battery level at a glance – Runs in the background while you use another app – Fast setup, nothing to sign up for

Works with your chest strap

Heart Alert is built for Bluetooth Low Energy (BLE) heart rate chest straps, including: – Polar H10, Polar H9, Polar H7 – Garmin HRM 600, HRM 200, HRM-Pro Plus, HRM-Pro, HRM-Fit, HRM-Dual – Wahoo TRACKR Heart Rate, TICKR, TICKR X – CooSpo H6, H808S, H9Z – Magene H64, H303 – Suunto Smart Heart Rate Belt – Decathlon Kiprun / Kalenji Dual HRM belt – iGPSPORT HR40, Moofit, XOSS, Bryton, Sigma and other generic BLE chest straps

Armbands and watches too

– Armbands: Polar Verity Sense, Polar OH1, Scosche Rhythm, Wahoo TICKR FIT, CooSpo HW807 – Watches that broadcast heart rate over Bluetooth: Garmin (Broadcast Heart Rate), Polar (share HR with other devices), Coros, Suunto, Amazfit, Huawei, Xiaomi Smart Band, Whoop

Turn on heart rate broadcast on your watch before you scan. Apple Watch, most Wear OS watches and Fitbit do not broadcast heart rate, so they cannot connect.

Any device that sends a standard Bluetooth LE heart rate signal should work, though Bluetooth on its own does not guarantee compatibility, and ANT+-only sensors will not connect. If yours is not detected, send the developer a message.

An external heart rate sensor is required. Camera-based measurement is not supported.

Made for

– Zone 2 work and aerobic base building – Running, cycling and indoor cycling – Cardio, gym sessions and interval training – Endurance and steady-state efforts – Easy recovery days, where the whole point is keeping the effort down – Anyone who wants a heart rate alarm and nothing else

Why an alarm instead of a display?

A number on a screen only helps if you look at it. An alert means your target range takes care of itself, and you only think about it when something actually needs attention — on the treadmill, on the road, or with your phone in a jersey pocket.

Pricing

Your first 5 tracking sessions are free. Unlimited tracking is a one-time purchase. No subscription, no ads.

Privacy

Heart Alert has no internet permission at all. Your heart rate never leaves your phone.

Important: background use

The app keeps tracking in the background, but Android may shut it down to save battery. To prevent this, see dontkillmyapp.com.

Heart Alert is a fitness and training tool. It is not a medical device, it is not intended to diagnose, treat, cure or prevent any disease, and it should not be relied on for emergency or continuous health monitoring. Check with a doctor if you have questions about your heart rate or your training.