What makes a good anchor alarm app
Before the list, here is what we judged them on. These are the features that separate an anchor alarm you trust from one you switch off after two false alarms:
- A loud background alarm. It must keep watching and be able to wake you with the screen off and the app in the background.
- A smart safe zone. A circle from your anchor and rode, ideally with custom shapes for tight or shoreline spots, so a normal swing does not trigger it.
- A swing track. A recorded track lets you see at a glance whether you are holding (a clean arc) or dragging (tracking off in one direction).
- Multi-device monitoring. Watch from a second phone or a laptop ashore, ideally without sharing one login.
- GPS options. Phone GPS is fine in open bays; external or NMEA GPS is far better in tight spots.
- Price and platform. Free vs subscription vs one-time, and whether it runs on your devices.
The comparison at a glance
| App | Platforms | Price | Multi-device watch | External / NMEA GPS | Languages | Store rating |
|---|---|---|---|---|---|---|
| Anchor Alarm Pro | iOS, Android, Web | Free, no account | Yes, via QR / code | Yes (Bluetooth, NMEA 0183, Signal K) | 13 | New in 2026 |
| Anchor Pro | iOS | Free + premium $6.99/yr | Via Telegram / email | Phone GPS only | 1 (English) | 4.8 (3,500+) |
| Ankeralarm (Anchor Alarm | Watch) | iOS, Android | Free + $22.99 once or $3.99 sub | Yes, two phones | Phone GPS only | 2 (English, German) | 4.7 (794) |
| Anchor Watch (High Hill Bits) | iOS | Free 10 alarms, then $4.99/yr | Via iCloud account | Phone GPS only | 2 (English, Norwegian) | 4.8 (24) |
| Anchor Alert (PredictWind) | iOS | $99/yr | Not listed | Phone GPS only | 1 (English) | 1.8 (4) |
Details from public App Store and Google Play listings, mid-2026. Prices in USD and subject to change.
1. Anchor Alarm Pro: best free, cross-platform pick
We will get our own app out of the way first, then let you judge the rest. Anchor Alarm Pro is free with no account and runs on iPhone, iPad, Android and in any browser, so you can leave one phone on the boat and watch from another device or a laptop ashore. Linking a second device is a QR code or a six-character code, with no shared login required.
The part we are most proud of is GPS. Where nearly every other consumer app can only use the phone's own GPS, Anchor Alarm Pro also connects to an external Bluetooth receiver, NMEA 0183 over the boat network, and Signal K, all at once, and auto-selects the most accurate live source with instant fallback. The drag alarm sounds a loud alarm right through the phone's own speaker, plus push notifications to your other devices, built in, with no Telegram bot or third-party service to wire up. It is genuinely new in 2026, so it does not yet have thousands of reviews, but the core watch is complete and free.
Try it in about a minute
Free to use, no account, no subscription. Put it on your phone or tablet, or just open the web watch in a browser to see how it feels before you rely on it.
2. Anchor Pro: the most-reviewed option
Anchor Pro (by IdeaBoys) is the heavyweight by review count, with a 4.8 rating from more than 3,500 users on iOS, plus an Apple Watch companion that shows distance, bearing and battery. The core drag alarm is free; a premium tier at $6.99 a year adds extras, and remote monitoring is handled through Telegram or email rather than a paired device. It is iOS-only, and like all continuous-GPS apps it can be hard on battery, so keep the boat phone on charge. If you live in the Apple ecosystem and want the most proven option, plenty of sailors rate it highly.
3. Ankeralarm (Anchor Alarm | Watch): best cross-platform paid app
Made by w+h GmbH, this is the one genuinely cross-platform competitor, on both iOS and Android, with a solid 4.7 from nearly 800 ratings. It offers meter-precision radius, polygon and angle monitoring for shoreline anchoring, and remote monitoring across two phones. The pricing is the fiddly part: a free tier, then a $3.99 subscription or a $22.99 one-time unlock, with the crowd-sourced anchorage search sold separately on top. If you want anchorage discovery and remote watch in one app across platforms, some might find it worth the money, just read the purchase options carefully.
4. Anchor Watch by High Hill Bits: privacy-focused iOS pick
A tidy, privacy-minded iOS app (with Apple Watch support) that gives you 10 free alarms before a very cheap subscription ($0.49 a month or $4.99 a year). It leans on Apple: remote monitoring works through your iCloud account with the location encrypted on Apple servers rather than shared to a third party, and it uses Critical Alerts to sound even when the phone is on silent. Ratings are strong (4.8) but from a small number of users. It may appeal if you value the Apple integration and no ads or tracking.
5. Anchor Alert by PredictWind: the pricey outlier
PredictWind, the weather-routing company, makes Anchor Alert. It covers the basics: drop an anchor, set a radius on a satellite chart, and get an alert if you drift outside it. The catch is the cost. The app is free to download, but a full anchor watch to match what the other apps here offer needs a PredictWind subscription at $99 a year, far more than anything else on this list. It is also iOS-only and English-only, and at the time of writing it carries a low App Store rating (1.8 from a handful of reviews). If you already pay for PredictWind forecasts it may be a convenient add-on, but as a standalone anchor watch it is hard to justify the price.
Honorable mentions
A few smaller apps are worth a look depending on your platform: HoldFast (iOS, free tier then $4.99/yr or $9.99 lifetime, built by a liveaboard and notable for alarming if it loses GPS), Anchory (iOS, around $5.99, with an augmented-reality anchor view), and Anchor Alarm - Anchor Watch by Florian Kriesche (iOS, $4.99 once, with custom alarm zones and your boat drawn to scale). On Android, webmajstr's Anchor (free, with a $5.99 Pro upgrade and roughly 260,000 installs) is a proven, low-cost option.
So which should you choose?
If you want a single free app that works on whatever devices your crew already carries, monitors from a second device without a shared login, and can read your boat's precise GPS, we would point you to Anchor Alarm Pro, though we admit we are biased. If you are iOS-only and want the most battle-tested option, Anchor Pro is a safe bet. If you need cross-platform plus anchorage discovery in one paid app, Ankeralarm is the pick. On Android, both Anchor Alarm Pro and Ankeralarm have you covered. And unless you already live in the PredictWind ecosystem, Anchor Alert is hard to justify at $99 a year.
Whichever you land on, the real win is simply having a watch you trust enough to leave running. For getting the most out of it, see our anchoring tips for a better hold, and if you run a chartplotter, how to use your NMEA GPS as an anchor alarm.
Frequently asked questions
What is the best anchor alarm app?
The best anchor alarm app is the one you will actually keep running every night: free, with a loud background drag alarm and multi-device monitoring. Anchor Alarm Pro covers iPhone, Android and the web for free, connects to external and NMEA GPS, and lets a second device watch over a shared code. Anchor Pro and Ankeralarm are also well-rated choices.
Is there a free anchor alarm app?
Yes. Anchor Alarm Pro is free with no account and no subscription on iPhone, Android and in a browser. Several others offer a limited free tier and then charge to unlock features such as background GPS or remote monitoring.
Do anchor alarm apps work with the app closed?
Good ones keep monitoring in the background and sound a loud alarm plus a push notification even with the screen off. On some apps, background GPS is a paid feature, so confirm it before you rely on it overnight.
Can I use my boat's chartplotter GPS for an anchor alarm?
Yes, if your app supports external GPS. Most only use the phone's internal GPS. Anchor Alarm Pro reads your boat's position over NMEA 0183 and Signal K, or from a Bluetooth receiver, which is more accurate and stable than a phone below decks.
App details, prices and ratings are from public store listings in mid-2026 and change often. This comparison is our opinion for general guidance; check each app yourself before relying on it as safety gear.