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Free to download. Requires Apple Watch Series 3 or newer (watchOS 8+).
A heart rate alert app turns your Apple Watch into something that taps you on the wrist the moment your heart rate crosses a limit you set. This is an honest, hands-on comparison of the dedicated threshold-alert apps worth knowing about in 2026, including where each one is strongest.
A heart rate alert app watches your heart rate while you go about your day and alerts you when it crosses a threshold you choose, instead of making you remember to check a number. The built-in high and low heart rate notifications on Apple Watch are useful, but they are delayed and only check periodically in the background. A dedicated app gives you customizable limits and an immediate alert the moment your heart rate crosses one.
Not every app in this category does the same thing. Some let you set both a high and a low threshold, some only watch the low end, and some are built around texting emergency contacts rather than day-to-day pacing. Here is what to look for before you compare them:
The ability to set your own high and low BPM limits, rather than relying on fixed values, so the app matches your routine.
A haptic and audio alert the instant your heart rate crosses a limit, not a number you have to remember to glance at.
Continued monitoring when your wrist is down or another app is open, so you are not limited to when you look at your watch.
Optional alerts on your iPhone that can cut through Silent Mode and Focus for moments when the watch alone is not enough.
Each of these apps takes a different approach. We have credited what each one does best so you can match the tool to what you actually need.
Beat Watcher lets you set customizable high and low BPM thresholds with the Digital Crown and alerts you with instant haptic and audio feedback the moment your heart rate crosses one. Background Mode keeps monitoring when your wrist is down or you switch to another app, and persistent alerts repeat until you respond so you do not miss the signal. An optional iPhone companion adds Critical Alerts that cut through Silent Mode and Focus, and Bluetooth chest strap support such as the Polar H10 is available for added accuracy. It is free to download, with an optional subscription of $12 per year that includes a one-month free trial. Requires Apple Watch Series 3 or newer on watchOS 8 or later. Distinctive strengths: persistent alerts, iPhone Critical Alerts, and a free download with $12-per-year pricing.
TachyMon runs on iPhone and Apple Watch with customizable upper and lower thresholds, and it can also alert you when your heart rate rises or falls a set amount from a recent rolling average. It was built with POTS in mind, its free tier covers the core alerts, and its premium tier of around $20 per year adds CSV and PDF data export plus iPhone-side sensor sessions. This is Beat Watcher’s closest direct alternative. Distinctive strengths: rolling-average alerts and paid data export.
Cardiac Alarm is a standalone Apple Watch and iPhone app focused on the low end only. It sounds a loud siren if your heart rate drops below a fixed value of 33 BPM or if the signal is lost. The low value is not customizable and there is no high threshold, so it is a narrow tool rather than a general pacing app. Distinctive strength: a simple, single-purpose low heart rate siren.
RscMe runs on Apple Watch and iPhone and is built around emergency SOS rather than day-to-day pacing. When your heart rate crosses a high or low limit you set, it can text up to five emergency contacts your name, your current heart rate, and a location link. Its SMS alerts use prepaid credits, so there is no subscription. Distinctive strength: alerting other people, not just yourself.
HeartWatch is a heart rate analytics app that tracks your daytime, sleep, and workout heart rate trends, and it includes background heart rate alerts. It is a one-time purchase of $8.99. Think of it as a richer-analytics alternative rather than a dedicated threshold-alert app. Distinctive strength: deep heart rate trends and history.
The right app depends on what you want it to do for you. Match your main goal to the strongest fit:
Beat Watcher and TachyMon are the two dedicated dual-threshold options. Beat Watcher leans toward persistent alerts and iPhone Critical Alerts; TachyMon leans toward rolling-average alerts and paid data export. Trying both is the fastest way to find your fit.
Cardiac Alarm is purpose-built for that, with a fixed 33 BPM siren. Just remember the value is not adjustable and there is no high threshold, so it will not help with tachycardia pacing.
RscMe is built around texting up to five emergency contacts when your heart rate crosses a limit, which is a different job than a personal pacing alert.
HeartWatch is the stronger fit for analyzing your heart rate over time across day, sleep, and workouts, rather than for dedicated real-time threshold alerting.
If you want a single recommendation for a dedicated heart rate alert app on Apple Watch, the honest answer is that it comes down to Beat Watcher or TachyMon, because they are the two apps built around customizable high and low thresholds for everyday use. Both let you try before paying: TachyMon has a free tier, and Beat Watcher is free to download with a one-month free trial. Beat Watcher is the stronger pick if you value persistent alerts that repeat until you respond, optional iPhone Critical Alerts that cut through Silent Mode and Focus, and its free download with an optional $12-per-year subscription. TachyMon is the stronger pick if you want alerts based on a rolling average or built-in CSV and PDF data export. Cardiac Alarm, RscMe, and HeartWatch are each excellent at their narrower jobs, a fixed low siren, emergency texting, and trend analytics respectively, but they are not direct substitutes for a customizable dual-threshold alert app. The best choice is the one whose strengths match what you will actually use, and since the leading options all let you try before paying, you can confirm the fit on your own wrist first.
Free to download. Requires Apple Watch Series 3 or newer (watchOS 8+).
There is no single best app for everyone, because the right one depends on what you want it to do. For day-to-day pacing with customizable high and low thresholds, Beat Watcher and TachyMon are the two dedicated dual-threshold options. Beat Watcher stands out for persistent alerts that repeat until you respond, optional iPhone Critical Alerts that cut through Silent Mode and Focus, and a free download with an optional subscription of $12 per year. TachyMon stands out for alerts based on a rolling average and paid data export. If you only want a low heart rate siren, Cardiac Alarm is purpose-built for that. If you want to text emergency contacts when your heart rate crosses a limit, RscMe is built around that. If you want richer trend analytics, HeartWatch is a stronger fit.
Yes. Beat Watcher is the closest direct alternative to TachyMon. Both let you set customizable upper and lower heart rate thresholds on Apple Watch and alert you when your heart rate crosses them. Beat Watcher adds persistent alerts that repeat until you respond and optional iPhone Critical Alerts that cut through Silent Mode and Focus, and it is free to download with an optional subscription of $12 per year. TachyMon offers alerts based on a rolling average and paid data export. Trying both is the best way to see which fits your routine.
Both apps let you set customizable high and low heart rate thresholds on Apple Watch and alert you when your heart rate crosses them, and both let you try the core alerts before paying (TachyMon has a free tier; Beat Watcher is free to download with a one-month free trial). The main differences are in extras. Beat Watcher offers persistent alerts that repeat until you respond, an optional iPhone companion with Critical Alerts that cut through Silent Mode and Focus, Bluetooth chest strap support such as the Polar H10, and an optional subscription of $12 per year with a one-month free trial. TachyMon can also alert you when your heart rate rises or falls a set amount from a recent rolling average, and its premium tier of around $20 per year adds CSV and PDF data export plus iPhone-side sensor sessions.
Beat Watcher, TachyMon, and RscMe all let you set both a high and a low heart rate limit. Beat Watcher and TachyMon are designed for day-to-day threshold alerting, while RscMe is built around texting emergency contacts when a limit is crossed. Cardiac Alarm only covers a low heart rate and uses a fixed value of 33 BPM that you cannot change, with no high threshold.
Pricing varies. Beat Watcher is free to download, with an optional subscription of $12 per year that includes a one-month free trial. TachyMon has a free tier covering core alerts, with a premium tier of around $20 per year that adds data export. RscMe has no subscription and uses prepaid credits for its text-message alerts. HeartWatch is a one-time purchase of $8.99. Many of these apps let you try core alerting before paying, so you can confirm the fit on your own wrist first.