It lives on your phone
Your card and your documents are encrypted on the device. Nothing is uploaded until you join a group that is allowed to see it.
How it works
From an empty card to a group who can answer for you
The same introduction the app gives you on the first run, in eight steps.
Last fix 14:05 · 2 min ago
Chamonix
Auvergne-Rhône-Alpes, France
lat45.9237° N
lon6.8694° E
accuracy± 8 m
altitude1,035 m
Emergency in France · 112
My groups
Mont Blanc traverse
BS
Balázs Szilágyi
Emergency card
A+
Penicillin
Asthma
MedicationSalbutamol
InsuranceEHIC · HU
In an emergencyAnna · +36 …
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Me
Trip mode is on
Mont Blanc traverse · 4 sharing · last position 14:05
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01
Open it and the local emergency number is there
The first screen shows where you are and the emergency number of the country you are standing in. No account, no signal and no card needed: the number comes from borders stored in the app, not from the network.
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02
Fill in your own card once
Name, blood type, allergies, conditions, medication, insurance and who to call. Every field is optional, and a blood type with one phone number already helps. It is encrypted on your phone, and nothing leaves it until you join a group.
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03
Photograph the documents you would hate to lose
Passport, insurance certificate, EHIC, driving licence. They stay encrypted on the phone and are only shared with a group that is allowed to see that part of your card.
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04
Make a group for the trip, or join one
Share a code or a QR, and the organiser accepts who comes in. The group has its own dates, its own files and its own route, and it ends when the trip does.
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05
Agree what that group sees before anyone joins
Sharing is set when the group is made. A hiking club can see medical details; a work trip sees a name and a phone number. Nobody joins without knowing which it is.
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06
Turn trip mode on while you are out
Between the trip’s dates, your position goes to that group so everyone can see each other on the map. Turn it off and it stops at once. Other syncing pauses to save battery and data.
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07
Hand the phone to whoever is helping
Open the card and tap a language: the labels and every answer chosen from a list are translated, and anything typed by hand is shown as written and marked. Or send the same card as a message.
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08
Leave when the trip is over
Leave the group and your card goes off the other phones the next time they connect. Delete your account and your card, files, groups and positions go with it.
Trip mode
Not tracking. Travelling together, for a few days.
Trip mode is the only time Petra records where anyone is, and it is the part people ask about first — so here it is in full.
- It exists only inside a group you chose to join, and only between the dates of that trip. Outside them, nothing is recorded at all.
- Everyone in the group is told when a trip starts and when it ends, on their own phone.
- Leaving the group stops it there and then, and your card comes off the other phones too.
- What the group sees is a rough last position and the time it was taken: a point every so often, not a line moving live across a map.
- A position can be old, missing, or out by a long way under trees, in a valley or between tall buildings. It narrows down where to look. It does not find anyone.
- Positions are deleted after 30 days, automatically. Changing a trip’s dates switches trip mode off for everyone and tells the group.
It is for people who agreed to look after each other for a few days — not for keeping an eye on somebody.
A
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Me
Trip mode is on
Mont Blanc traverse · 4 sharing · last position 14:05
Why it is safe to put this in one place
Each group sees its own version
Medical details go only to the groups you turned them on for. A tour guide does not become someone who knows everything about you.
Nobody is tracked between trips
Positions exist only while trip mode is on, during the trip’s dates, and they are deleted after 30 days.
Leaving takes everything with you
Leave a group and your card is removed from the other phones. Delete your account and everything goes.
Who it is for
Petra was built for groups who are responsible for each other for a few days at a time.
Hiking and mountain groups
If one of us gets hurt, the rest can speak for them
The group agrees before setting off what it shares. If someone is injured, unconscious or separated from their phone, anyone in the group can give the ambulance and the insurer what they ask for, and show where the person was last seen.
Travelling abroad
One place for the papers everyone keeps losing
Passport and ID scans, insurance certificates, tickets, accommodation confirmations and maps live in the group instead of scattered across four chats, readable with no signal and no roaming. They do not replace the real papers — they mean nobody is stuck because the person holding them is elsewhere.
Trail runners, solo hikers, cyclists
Somebody knows where you are today
Make a group with one friend, set it for the hours you are out, and they can follow along. They see roughly where you were and when — enough to know you are moving, and where to start looking if you stop.
Guides and city tours
You are responsible for people you have never met
Guests join the group with a code or a QR before you set off, and bring their own emergency contacts, conditions and insurance with them. You are not carrying a folder of photocopies, and you are not asking strangers about their health in front of a group.
Schools, clubs, ski trips
Collect it once, from everyone, without paperwork
Twenty families fill in their own details instead of twenty forms coming back half empty. Leaders see what the group agreed to share, and the list stops being out of date the moment somebody changes a phone number.
Petra is in testing
It is not in the App Store or Google Play yet. Write to us if you want to try an early build with your group, or if you run a club, a school trip or tours and want to talk about it.