Your family stays reachable — even without a network
Supplies and how long they last, meeting points and family status, alerts for your places — and radio when the mobile network fails.
Who is where, who is okay, where do we meet. One tap sends the status to every device in the family; meeting points and SOS are visible to all. When the mobile network fails, a small LoRa radio next to the phone takes over — messages and positions travel from device to device, no tower, no server. And the app calculates with your numbers: how long your supplies last, how a blackout unfolds for you, where fallout drifts — all on the device. Plus alerts for your places, an offline map and a simple view for kids.
Prepper is no substitute for emergency services or official warnings.
If life is at risk: call 112 (911 in the US and Canada). Alerts in the app come from public sources and may be late or missing. Notifications, chat and radio depend on devices, batteries and networks. The app helps a family find each other and be prepared — the responsibility for decisions stays with you.
The warning tells you what is coming. Prepper keeps the family together.
Family status
One tap: “I’m fine” or “Need help” — with position and battery, on every family device.
Everyone report in
One question to all: “All good?” Over internet and radio at once. After a minute you see who answered.
Meeting points
A, B, C — visible to all, with distance from every device. Whoever can’t reach the first goes to the next.
Reachable without a mobile network
A small LoRa radio next to the phone, and messages, status and positions travel device to device. No tower, no server.
For kids
A simple view with big buttons: I’m fine, Family, Meeting point, Map, Radio. And help, if it comes to that.
No account, no sign-up
Create a household, show the QR code, done. No e-mail, no password, no registration queue.
Four stages — one app
Notice early, inform the family, act together, keep working offline — and when even the mobile network is gone, stay connected by radio. The official warning apps tell you what is coming. Prepper makes sure the family finds each other then.
Before
The watchman checks warnings and early indicators for your places around the clock and only speaks up when it concerns you.
During the crisis
Family · emergency plan · map · supplies · routes · meeting points · checklists — all on every phone in the household.
Internet gone
Offline maps and all data live on the device. The app keeps running as if nothing happened.
Mobile network gone
Meshtastic radio (LoRa) takes over: chat, position and SOS between the family devices — and the base station at home keeps relaying warnings as long as it has power. Which device for what →
The situation — right now
This is what the watcher sees every five minutes. In the app the same map lives on your phone offline, with your own alert locations on it.
Watcher last run: – · Sources: EMSC, GDACS (EU/UN), Netzfrequenz.info, aWATTar, Austrian and German radiation monitoring networks, Lower Austria gauges, air-raid services UA/IL/TW, GeoSphere Austria (per alert location in the app)
A watcher that never sleeps
Checklists are everywhere. This isn't: a server checks around the clock the sources that hint at danger before it makes the news — and only speaks up when it concerns you. Official weather alerts cover about 40 countries — in the US every state (National Weather Service). Austria has the densest coverage, including radiation and river gauges. The world situation works anywhere.
Three kinds of messages, clearly separated: Early indicator — a hint, not yet an event (grid frequency, power price, air alerts elsewhere). Warning — officially issued (weather, floods). Event — measured or confirmed (earthquakes, radioactivity, major disasters).
Official weather alerts
AustriaFor each of your places separately — home, school, retreat. From the level you choose.
Power-grid early warning
Grid: continental Europe · price: AustriaGrid frequency every minute: unusual deviations point to stress in the European grid — an early indicator, not a blackout forecast. And tomorrow's power market: a price spike means scarcity with hours of lead time — time to charge the EV.
Radioactivity and floods
Radiation: Austria + Germany · gauges: Lower AustriaAround 1,800 stations of the radiation monitoring networks in Austria and Germany, each against its own baseline. River gauges around your places from the yearly flood level up.
World situation and early indicators
worldwideEarthquakes and major disasters with distance to you. Air raids in conflict regions as a sign of escalation — no local danger, but a reason to look.
Daily briefing with AI
worldwideEvery morning a short assessment for your household: weather at your places, alerts, supplies, what to do today. And on demand: "What now?"
Your own sources
worldwideAny alert service that provides a feed can be attached — whatever country you live in.
A toolbox that works without a network
Offline map and routes
Save map areas to the device, precompute escape routes and share them with the household. GPS guides you without coverage. How the offline map works →
Fallout calculator
Bomb or reactor accident: choose the impact — major city, nuclear plant, military base or a point on the map — and the app uses the real wind at ground level and aloft to work out where the cloud goes. For you and your alert places: affected or not, when it arrives, how long you must stay inside, whether there is still time to leave. Rings and plume on the map. Works offline, for your places.
Blackout clock
How a power outage unfolds for you, hour 0 to day 30: on the left what fails outside (mobile network after 4 hours, water, freezer, supermarkets), on the right what you still have at each point — calculated from your supplies, energy and people, with the season: PV yield, outside temperature, daylight. Above it the sentence that counts: "First bottleneck: warmth on day 1." And the levers that change it.
SOS
One button alerts your family — with location and battery level. Not a replacement for emergency services, which are always right next to it.
Family chat and groups
Encrypted, buffered offline. And beyond the household: families link up in groups, share places, routes and who can do what — doctor, electrician, farmer.
Radio without a network
A small LoRa radio (Meshtastic, from about 30 euros / $35) connects to the phone by Bluetooth. Chat and SOS then work without a mobile network or internet — the devices form their own network, a base station at the house reaches for kilometres.
Tools without a network
Compass with an arrow to the meeting point or family, distance on the map, how long until dark, SOS flashing and Morse, storm distance, your own coordinates to read out. And a fallout calculator: bomb or reactor, real wind, arrival time, how long to stay inside. Everything runs on the phone alone.
Supplies and endurance
Scan, photograph the shelf, done. The app works out water and calories per person — children differently from adults — and tells you how many days you last. Per location, with power, medication and heating — and at the tap of a button with half rations. Shopping list for 14 days →
People and documents
Blood type, medication, IDs as photos — encrypted, the key stays in the household. We can't read them either.
Emergency plans, checklists, know-how
Blackout, flood, evacuation: activate an emergency plan and everyone in the household sees the immediate steps. Guides live offline on the device.
Getting started
No registration, no credit card, connected in two minutes.
Get the app
iPhone: on the App Store. Android: app package from the developer. On a computer or without installing: app.prepper.team in the browser — everything except radio.
Create a household, add the family via QR
One phone creates the household and shows a QR code. Every other phone scans it in the app — done. No account, no e-mail, no password.
Alert places, notifications, radio
Enter your places and turn on notifications — from then on the server keeps watch. If you have a Meshtastic radio: connect it in the app, tap “Set up”, and the family stays reachable even without a network.
The app version with radio in the background
For Android, Prepper is available as an app package directly from the developer, with checksum and version. What that means and how installation works is explained on its own page.
See the Android versionWhat you can count on
- The app is fully usable without signing in — no login screen in your way when it matters.
- Map, routes, supplies, know-how and checklists work fully offline.
- Alerts need a network on the receiving end. In the middle of a blackout nothing gets through — true for every app. That's why the watcher warns you beforehand.
- Official weather alerts cover about 40 countries — in the US every state. Radiation and river gauges are currently available for Austria. World situation, earthquakes, grid frequency and your own feeds work everywhere.
- A private project, built for our own family. There is no company behind it and no guarantee — but someone who uses it himself every single day.
What happens to your data
- Prepper is no substitute for emergency services or official warnings. If life is at risk: call 112 (911 in the US and Canada). Alerts come from public sources and may be late or missing; notifications, chat and radio depend on devices, batteries and networks. The app is a family aid, not a guarantee.
- No account, no e-mail, no name required. A household is a number with a join code.
- The server is in Nuremberg (Germany). It stores: the household data you sync (lists, supplies, markers), your alert places and the push addresses of your devices.
- Chat messages, family status, locations and document photos are end-to-end encrypted. The key is created on your first device, moves to new devices by itself and never leaves the household. Only a help call is deliberately left open so it reaches every device at once.
- Location is only shared if you switch it on, and only while the app is open. The last point is stored, never a track.
- Groups are shared by design: what you release there (household name, skills, resources, a contact, a location) is visible to every member of that group and is stored on the server without end-to-end encryption. Release only what the group should know.
- For operation, the server keeps a technical log (IP address for abuse protection, errors, household and device numbers), and the operator gets a short notice when a new household is created — the household name, nothing else.
- For the daily briefing an AI model receives your alert places, supply quantities and people as age groups — no names, no diagnoses, no chats.
- No ads, no analytics services, no sharing. You delete everything local yourself in Settings, everything on the server with one e-mail.
Support the project
Prepper is free and stays free. Servers, map data and the AI still cost money — about 20 euros a month. Chip in if you like. If not, use the app just the same.
Just as valuable: show the app to a family who could use it.