GPS Location Alarm for Android

Sleep on your commute. Never miss your stop.

Nap Alarm is a GPS location alarm for trains, buses, metros and other journeys. Set your destination, choose how far out you want waking, and the alarm sounds as you approach — not at a clock time you had to guess before you set off.

It is designed to cut the risk of sleeping past your stop, not to guarantee it away: the alarm needs a location fix, and underground it works from an estimate. What it can and can't do.

Get it on Google Play See How It Works

Free to download·Android·Optional Pro

iOS App coming soon

You can't set a clock alarm for a journey you can't time

To set a normal alarm for your commute, you have to guess the journey length before you leave. Public transport doesn't cooperate — and it fails in both directions.

A clock alarm measures time

Run late and it wakes you two stops early — you see you're not there, go back to sleep, and now nothing is coming. Run early and it goes off after you've already passed your stop. The early failure is the one that actually costs people their stop.

A GPS alarm measures distance

Nap Alarm watches the gap between you and the destination you picked, and sounds when it closes to a distance you chose. A delay makes the journey longer. It doesn't move the destination.

The trade-offs both ways — including when a normal alarm is still the better tool — are set out in GPS alarm vs a normal alarm, and how a location alarm decides when to fire covers the two trigger modes.

How the location-based alarm works

Three steps before you sleep, then the app does the watching.

Set Destination

Search for your train station, bus stop, or save your Home/Work coordinates for instant 1-tap route setup.

Choose a Buffer

Choose how much warning you want — a number of minutes before you arrive, or a distance from your stop. Which one suits you depends on how you are travelling.

Go to Sleep

Lock your phone and rest. A background service keeps tracking your progress with the screen off, and sounds the alarm as you approach your stop.

Setting it up for your journey

Train and bus journeys need different alarm settings, because the distance between stops varies so much between them. These pages go into the numbers for each.

How a GPS alarm works

What a location alarm measures, the two ways it can decide to fire, how to choose a trigger distance — and what it can't do.

Train alarm

Long gaps between stations change how you should set the buffer — and what happens if you sleep past the terminus.

Bus stop alarm

Bus stops sit a few hundred metres apart, which makes buffer choice and trigger mode matter far more than on rail.

Subway & metro alarm

What the app does in the minutes after GPS drops out in a tunnel — and the limits of predicting your position.

GPS alarm vs a normal alarm

Why a clock alarm fails the moment your service runs late or early, and when it's still the better tool.

Trip Buddy for solo commuters

Pair with a friend. If you don't respond at your stop, they get a siren, your live location, and a one-tap call.

GPS alarm apps compared

An honest look at the main Android options, including the cases where another app is the better pick.

What the GPS alarm does during your journey

Eight features shaped around what actually goes wrong on a train, bus or metro journey. Anything in the optional Pro tier is marked as such.

Smart ETA Tracking

Time-Based mode recalculates your arrival time as traffic and transit delays change, so the alarm moves with your journey instead of firing at a fixed clock time.

Distance-Based Alarms

Distance mode fires when you cross into a radius you set around the destination, whatever the traffic is doing. It suits closely spaced stops on local bus routes.

Anti-Theft Shield 🛡️

Arm the shield before you sleep and the app watches the accelerometer, sounding a loud, distinct alarm if the phone is unplugged, moved sharply, or picked up.

Smart Audio Routing

If headphones are connected, the alarm plays through them rather than waking the whole carriage. If they are not, it plays through the speaker.

Alerts Built to Get Through

Runs as an Android foreground service with Doze-aware scheduling, so tracking keeps going with the screen off and the app swiped out of recents. The alarm is designed to sound through the lock screen and silent mode.

Battery Optimized

GPS polling is paced against your current travel speed and remaining distance rather than running flat out, so the app checks your position less often when it doesn't need to.

Subway Watchdog 🚇

There is no satellite fix in a tunnel. After two minutes without one, Subway Watchdog estimates your position from your saved route and its stop timings rather than waiting for the signal to come back.

Smart Geofence Reminders 📍Pro

The app notices when you leave a saved location like Home or Work and reminds you to set your alarm, so arming it is not something you have to remember on the platform.

Subway Mode

GPS can stop underground. Your alarm can keep going.

There is no satellite fix to read the moment you enter a subway tunnel, so location tracking simply stops. Nap Alarm's Subway Watchdog treats sustained signal loss as information rather than failure: it switches to predictive tracking and keeps counting your stops from your saved route until the train resurfaces.

2-Minute Detection Window
If GPS signal drops for more than 2 continuous minutes, Subway Watchdog activates automatically — no input required.
Predictive Stop Tracking
Uses your saved route and its average stop intervals to estimate where you are while the signal is gone, instead of waiting for it to return.
Handoff Back to GPS
The moment you resurface and a real fix returns, tracking snaps back to live GPS and the estimate is discarded.

Worth being straight about: predictive tracking is an estimate, not a GPS measurement. Delays, longer-than-usual dwell time at a station, an unscheduled hold in a tunnel, a diverted route, or a line you have never travelled with the app all push the estimate away from where you actually are — which is why a wider buffer helps underground. How it works, and where it falls short.

New Release

Meet Trip Buddy.
A friend who gets told if you don't wake up.

Don't just sleep comfortably — sleep safely. Nap Alarm watches whether you respond to the arrival alarm, and only alerts the friend you paired with if you don't.

It escalates on its own
If the arrival alarm sounds and nothing stops it within the expected window, the app alerts your paired buddy without you having to do anything. It alerts that person — not the emergency services.
Shared Only in an Emergency
Pairing does not grant ongoing tracking. Your buddy sees your location only when you have an active trip and an emergency has been triggered.
Live Location for Your Buddy
While the SOS is active, your buddy sees your position on a map and can reach you with a one-tap call. It stops the moment you cancel the alarm.

Trip Buddy is a way of reaching one person you chose in advance. It is not an emergency service and does not contact one. Getting the alert through depends on pairing beforehand, on both phones having a connection at the time, and on your buddy having notifications enabled — so treat it as a backstop, not a guarantee. How Trip Buddy works.

Before you grant location access

A commute alarm only works if it can see where you are, so it is fair to want the details first. Here they are, in plain terms.

Why it asks for background location

The alarm has to know where you are while your screen is off and the app isn't in front of you — that is the whole job. Android classifies that as background location, which is why the permission prompt looks alarming. Without it, tracking stops the moment you lock the phone.

The alarm itself runs on your device

Once your route is set, the app doesn't need an internet connection to track your position and sound the alarm. Comparing where you are against where you're going happens on the phone. Tracking runs in an Android foreground service, so it carries on with the screen off and the phone locked — you will see a persistent notification while a trip is active, which is Android's requirement for any app doing this, and your cue that it is still running.

When your location does leave the phone

Two cases, and they're worth knowing separately. Trip Buddy shares your live location with a friend you paired with in advance — but only during an active trip where an emergency has been triggered, never as ongoing tracking, and it stops the moment you stop the alarm. Separately, the privacy policy sets out that anonymised location data may be sent to third-party services for analytics.

Deleting your data

Settings → Delete Account erases your cloud data from inside the app. If you've already uninstalled, emailing support gets it done manually within 7 days. Uninstalling on its own stops any further collection.

The app is free to download and ad-supported, so it is worth naming what that means: ads are served by Google AdMob, Firebase handles sign-in and syncs your account data, and Google Play Services provides the location APIs underneath all of it. Each one receives something — the privacy policy sets out the detail. Anything unclear, ask us at support.napalarm@gmail.com.

Frequently Asked Questions

Everything you need to know

Questions about the location-based alarm for commuters? We've got answers.

General

A normal alarm fires at a clock time you set in advance, which means guessing how long your journey will take. A GPS alarm ignores the clock and watches your position instead, sounding when you come within a distance you chose of your destination. A delay makes the journey longer; it doesn't move the destination — which is why a location alarm suits public transport and a clock alarm doesn't.

Yes — free to download, with optional Pro features. The core location alarm, Subway Watchdog, Trip Buddy and the Anti-Theft Shield are all in the free, ad-supported app. Gentle Wake, Smart Reminders and trip history sit in the Pro tier, which you can unlock with Z-Coins earned by watching ads or buy outright as a one-time Lifetime Pro purchase that also removes the ads.

Nap Alarm is on the Google Play Store, for Android devices. It isn't tied to a particular city or transit operator — you set your own destination, so it works on whatever route you travel. There is no iOS version yet.

How It Works

Open the app, search for your destination station or bus stop, set a proximity buffer (e.g. wake me 500m before I arrive), then lock your phone and sleep. Nap Alarm runs a native background service that continuously checks your position and fires the alarm when you enter the buffer zone — no internet required after the route is set.

Yes, and you should — being woken at your stop means standing up in a hurry. You can set a custom proximity buffer anywhere from 200 m to 5 km, shown in kilometres, metres, miles or feet depending on the units you pick. There is also a time-based mode that wakes you a set number of minutes before your projected arrival, recalculated as delays change.

Yes. Tracking runs in an Android foreground service, which operates independently of the screen state and survives the app being swiped out of recents, so the alarm still fires with the screen off and the phone locked. One thing worth knowing: some Android manufacturers apply their own aggressive battery restrictions on top of stock Android. If your device does that, exempting Nap Alarm from battery optimisation in your system settings is the reliable fix.

Any app that tracks your position continuously uses some battery — there is no way around that. Nap Alarm is built to keep it down: the background location worker uses Doze-aware scheduling and paces its GPS polling against your travel speed and remaining distance, rather than polling at a fixed high rate for the whole journey. Actual drain depends on your device, your route length, and how strong the GPS signal is.

Subway & Underground

This is the feature Nap Alarm is built around. After two continuous minutes without a GPS fix — typically when you enter a tunnel — Subway Watchdog activates on its own and switches to predictive tracking rather than waiting for the signal to return, using your saved route and its average stop intervals to keep advancing an estimate of where you are. It hands back to live GPS the moment the train resurfaces. Because it is an estimate and not a measurement, delays, long dwell times and diversions all push it off, so a wider buffer gives it room to be slightly early rather than slightly late.

Subway Watchdog isn't tied to a particular city or operator — it keys off GPS availability, so it applies on any underground system where the signal drops, including those three. Because the prediction is built from your own saved route and stop timings, it has more to work from on a line you travel regularly than on one you're riding for the first time.

Safety & Features

Trip Buddy pairs you with someone you trust using a six-digit code you generate in the app, in one-way or two-way mode. It arms itself only during an active trip: if the arrival alarm sounds at your destination and nobody stops it within the expected window, the app treats you as unresponsive and alerts your buddy with your live location and a one-tap call button, playing a siren that is designed to cut through Do Not Disturb. Stopping the alarm deletes the emergency and mutes their siren straight away.

No. Pairing does not grant ongoing tracking. Your location is shared only when both conditions are true — you have an active trip and the emergency has been triggered — and it stops as soon as you stop the alarm. Worth knowing that Trip Buddy alerts the person you paired with, not the emergency services, and getting the alert through depends on both phones having a connection and on your buddy having notifications enabled.

Arm the Anti-Theft Shield before you sleep and the app watches for the signs of your phone being taken — unplugged from its charger, moved sharply, or picked up. It sounds an immediate, distinct alarm without waiting for your location alarm to be due.

Still have questions? Contact support

Get Nap Alarm on Google Play

Ready to use a GPS alarm for train, bus & subway?

Set your destination, pick how far out you want waking, and sleep. Your GPS alarm for train, bus & subway is free to download on Android, with optional Pro features.

Free to download·Android·Optional Pro

Get it on Google Play

iOS App coming soon

The rest of the app

None of this is the reason to install Nap Alarm — the alarm is. But it is what you will find once you are using it.

Sleep stats and ranks

The app logs how long you sleep on each trip and totals it up over time, with ranks and milestone titles as the total grows. The record syncs to your account, so it survives a reinstall.

Z-Coins and Pro

The location alarm is free. Optional Pro features — Gentle Wake, Smart Reminders and trip history — unlock with Z-Coins earned by watching ads or completing daily commutes, or with a one-time Lifetime Pro purchase that also removes the ads.

Refer a friend

Share your invite code from the app's side menu. Once a friend signs up with it and completes their first trip, you both get a few days of Pro access.

Nap Route

When several routes reach the same destination, Nap Route favours the ones with fewest transfers — a longer unbroken stretch you can actually sleep through.

What the alarm itself does, and where it falls short, is covered on the GPS alarm page.

Sleep on your commute. Never miss your stop.

You can't set a clock alarm for a journey you can't time

A clock alarm measures time

A GPS alarm measures distance

How the location-based alarm works

Set Destination

Choose a Buffer

Go to Sleep

Setting it up for your journey

How a GPS alarm works

Train alarm

Bus stop alarm

Subway & metro alarm

GPS alarm vs a normal alarm

Trip Buddy for solo commuters

GPS alarm apps compared

What the GPS alarm does during your journey

Smart ETA Tracking

Distance-Based Alarms

Anti-Theft Shield 🛡️

Smart Audio Routing

Alerts Built to Get Through

Battery Optimized

Subway Watchdog 🚇

Smart Geofence Reminders 📍Pro

GPS can stop underground. Your alarm can keep going.

2-Minute Detection Window

Predictive Stop Tracking

Handoff Back to GPS

Meet Trip Buddy.A friend who gets told if you don't wake up.

It escalates on its own

Shared Only in an Emergency

Live Location for Your Buddy

Before you grant location access

Why it asks for background location

The alarm itself runs on your device

When your location does leave the phone

Deleting your data

Everything you need to know

General

How It Works

Subway & Underground

Safety & Features

Ready to use a GPS alarm for train, bus & subway?

The rest of the app

Sleep stats and ranks

Z-Coins and Pro

Refer a friend

Nap Route

You can't set a clock alarm for a journey you can't time

A clock alarm measures time

A GPS alarm measures distance

How the location-based alarm works

Set Destination

Choose a Buffer

Go to Sleep

What the GPS alarm does during your journey

Smart ETA Tracking

Distance-Based Alarms

Anti-Theft Shield 🛡️

Smart Audio Routing

Alerts Built to Get Through

Battery Optimized

Subway Watchdog 🚇

Smart Geofence Reminders 📍Pro

GPS can stop underground. Your alarm can keep going.

2-Minute Detection Window

Predictive Stop Tracking

Handoff Back to GPS

Meet Trip Buddy.A friend who gets told if you don't wake up.

It escalates on its own

Shared Only in an Emergency

Live Location for Your Buddy

Before you grant location access

Why it asks for background location

The alarm itself runs on your device

When your location does leave the phone

Deleting your data

Everything you need to know

General

Meet Trip Buddy.
A friend who gets told if you don't wake up.

Meet Trip Buddy.
A friend who gets told if you don't wake up.