In late 2020, journalists at Vice's Motherboard reported something that made many Muslims go quiet. Location data from a hugely popular Muslim prayer app had reportedly flowed to a data broker, and from there to buyers that included U.S. military contractors. The app's makers said they had ended the relationship once the story broke. But the feeling it left behind was harder to end: the thing you open to talk to God five times a day had, perhaps, been quietly keeping a diary of where you stood while you did.

That feeling is worth taking seriously. Prayer is about as private an act as a person has. Where and when you pray can reveal your faith, your routine, your workplace, your mosque, your travel. In some places, that is simply sensitive. In others, it is dangerous.

The good news is that the mathematics of prayer times is astonishingly modest. What it needs from you is small. Once you see how small, you can judge for yourself when an app asks for far more.

What a prayer time actually is

A prayer time is not data to be fetched from a server. It is geometry.

Fajr, Dhuhr, Asr, Maghrib and Isha are defined by the sun's position in the sky: the angle below the horizon at dawn, the moment it crosses its highest point, the length of an object's shadow, the instant of sunset, the end of twilight. Astronomers can compute all of this from only a handful of inputs: your latitude, your longitude, the date, your time zone, and a few choices you make, like the calculation method and the Asr school.

That is the whole list. Nothing in it requires your name, your contacts, your advertising ID, or knowing where you were at 3:14 yesterday afternoon.

Better still, the computation can run entirely on your phone. No internet connection is needed to work out when the sun sets in a given place on a given day. An app that calculates on-device can work in airplane mode, in the desert, in a basement, and it can do all of it without telling anyone anything.

How precise does your location need to be?

Less than you would think. Here is a bit of arithmetic. The Earth turns 15 degrees of longitude per hour, so one degree is four minutes of solar time. At mid-latitudes, one degree of longitude spans roughly 80 to 90 kilometres. Move ten kilometres east or west and your prayer times shift by around half a minute.

Most people's mosques, and most communities' published timetables, round to the minute anyway. A city-level location is, for practical purposes, as good as your exact street address. Your prayer times in a city of three million people are the same whether you are standing in the north end or the south end.

Qibla is similar. It is the great-circle direction from where you are to the Kaaba, and again a coordinate for your city gives a bearing within a degree or two. The compass that points you there reads your phone's magnetometer, a sensor on the device. It does not phone home.

So here is the uncomfortable question that follows. If everything a prayer app needs fits inside a city name, why would it ever want continuous, precise, background location?

Where the extra data usually comes from

The answer is usually money, not prayer. Free apps need revenue, and one common route is advertising. Ad networks and analytics software bundled into an app can collect device identifiers, approximate or precise location, and usage patterns. Some of that data is passed along and combined with other sources by brokers, who sell the results.

This is not unique to prayer apps. It is how a lot of free software works. What makes it feel different here is the nature of the information. A weather app that leaks your location is a nuisance. A faith app that leaks it is leaking something closer to the soul.

It is also worth saying that not every app with ads is malicious, and not every ad-free app is automatically clean. The point isn't to panic. It is to stop treating the permission prompt as a hurdle to tap through and start treating it as the one moment you get a vote.

The quiet cost of being watched

There is a psychological side to this too. Researchers who study surveillance and behaviour have long described a chilling effect: when people believe they are being observed, they tend to change what they do, often avoiding things that feel sensitive or might be misread. For a worshipper, that can mean subtle self-censorship, a flicker of unease before opening the app, or a reluctance to track a practice that ought to feel like home.

Prayer asks for a particular kind of openness. Whatever quietly erodes your sense that this space is yours erodes some of what the practice is for. Privacy here isn't a technical luxury. It protects the ease you bring to the act.

Your next moves

You can audit your own prayer app in about ten minutes. Here is how.

  • Check the location permission. On iPhone, go to Settings, then Privacy & Security, then Location Services, and find your prayer app. Choose "While Using the App" at most, never "Always." On Android, open the app's permissions and choose "Only while using the app."
  • Turn off precise location. Both iOS and recent versions of Android let you grant approximate location instead. For prayer times and Qibla, approximate is plenty. If the app stops working properly with approximate location, that tells you something.
  • Read the privacy label. On the App Store, scroll to "App Privacy." Look for categories like "Data Used to Track You" and "Location." On Google Play, check the "Data safety" section. Compare what is collected with what the app plainly needs.
  • Run the airplane-mode test. Switch on airplane mode and open the app. Do today's prayer times and the Qibla compass still work? If so, the calculation is happening on your device. If it breaks, the app depends on a server, which is worth asking about.
  • Set your city by hand. If your app lets you enter a city manually instead of using GPS, try it. You lose nothing, and the app no longer needs to know where you walk during the day.

If an app fails most of these, you do not have to delete it in anger. But you now know what you are trading, and you can decide on purpose rather than by default.

What good looks like

A respectful prayer app is, in a sense, boring. It asks for a location once, or only while it is open, and uses it to compute five times. It stores your calculation method and Asr preference on your device. It shows no ads, loads no tracking software, and has no need to build a profile of you, because your prayer times do not depend on one.

That is the idea behind Athan: daily prayer times and Qibla, with no ads and no creep. It was built on the premise that the sun is public and your whereabouts are not, and that everything the app needs to do can be done with that in mind. If you want a quieter way to keep your five prayers, you can see how it works at athan.lumenlabs.works. Whichever app you use, the most important thing is that it leaves you feeling unobserved when you stand to pray.