JervYour map of Earth starts blacked out.
Every street you walk, run, ride or roll uncovers it — and it stays uncovered. Not for the week. For good.
Free, through TestFlight. Android beta opens soon — see how it works in the meantime.
How the fog works
Three things happen, and the third is the one every other app gets wrong.
Record a trip
Walk, run, cycle, skate, wheel. The phone records where you actually went, at street resolution — squares of about fifty metres a side in Europe, a little larger nearer the equator.
The fog pulls back
Every square you pass through opens permanently. Squares nobody has reached yet are still sitting there, unclaimed — and the first person through takes them.
It never closes again
A fitness app draws a line where you went and has forgotten it by Sunday. Jerv keeps the whole of it, for as long as you keep the account.
Everywhere you have been, in one place
The line was never the interesting part. The territory is.
Permanent fog
Uncovered ground stays uncovered. Your map is a record of years, not a chart that resets on Monday.
First footers
Be the first person ever to cross a square and it is marked as yours, permanently. Cities have more unclaimed ground than you would guess.
Territory you can lose
Blocks you visit often are held in your name. Stop going and they decay, and somebody else takes them.
Boards worth being on
Nearby, area, friends and global — plus a season board that resets, which is the one a new explorer can actually win.
Finds on the ground
A nightly pass scatters finds across real places near active explorers. Pass through the block and it settles with the trip.
Streaks and milestones
Twenty-four achievements, from your first hundred squares to an eight-by-eight block of finished tiles.
Every trip pays out
Ground you have never covered, Spor, a streak that has to be fed, and the finds you passed — totalled the moment you stop, and counted by the server rather than the phone.
A map, not a training log
There are good apps for pace, splits and heart rate. This is not one of them, and it is not trying to be.
What Jerv keeps
- Every square you have ever been through, permanently
- Which of them nobody had reached before you
- The shape of the ground you hold right now
- How much of a tile you have finished, and which corners are missing
What a training log keeps
- A line, drawn on top of last week's line
- A pace you will not remember on Sunday
- A weekly total that resets
- A heat map that fades the moment you take a month off
Where you have been is the most sensitive thing you own
Jerv has no advertising identifiers, no device fingerprinting, and no third-party analytics or crash SDK anywhere in the app. Nothing about where you go is sold, shared or brokered. You can draw a zone around your home and the squares inside it never leave the phone — and the privacy policy is honest about the one thing a zone cannot do, which is reach back and un-upload what already went.
Frequently asked questions
What is a fog of war map app?
It borrows the idea from strategy games: the world starts hidden, and it is revealed by going there. A fog of war map app applies that to the real world — your own map of Earth is blacked out until you physically travel through a place, and what you uncover stays uncovered. Jerv uncovers in squares of about fifty metres a side at European latitudes (a little larger nearer the equator), which is street resolution rather than neighbourhood resolution.
How is this different from a Strava heat map?
A heat map shows where you go often, and it fades. Jerv is a record of where you have ever been, and it does not. The heat map is about frequency; this is about coverage — and about the ground nobody has covered yet, which is where the first-footer claims come from.
Does it work for walking, or only cycling?
Walking, running, cycling, e-bike, skating, wheelchair, unicycle. The squares do not care how you got there, and the anti-cheat is about ruling out driving rather than about picking a sport.
What platforms does it run on?
You play it on a phone. The iPhone and Android apps are what record a trip and draw the fog as you move — browser geolocation cannot do that properly in the background. The iPhone app is in open beta now, free through TestFlight; the Android beta opens soon. There is also my.jerv.app, which works in any browser and is where you go afterwards to look at your map, your numbers, your trips and the boards. It reads; it does not record.
Is it free?
Yes, and it is free during the beta with no per-trip limits. There is no advertising and nothing about where you go is for sale, which means it will not be funded that way later either.
Can other people see where I live?
Not unless you decide they can. A profile is private until you make it public, and even then you can draw a zone around home whose squares are stripped before anything is uploaded. The boards show counts and territory, never a track.
What does “Jerv” mean?
It is Norwegian for the wolverine — an animal that covers an implausible amount of ground for its size. Pronounced yairv.
Where to start
How much of a city is actually walkable in a year, and what it takes to cover one. Free to read, no account.
Start uncovering
Free. No trip limits, no advertising, and nothing about where you go for sale.
Free on iPhone through TestFlight. The Android beta opens soon.