Why I built a prayer times app

I’m a Muslim, and I try to pray the five daily prayers on time. I don’t always manage it. Some days I miss one, and I do my best. Each prayer has a window, and the times shift a little every day and from place to place. So, like most Muslims with a phone, I rely on a prayer times app.

What I need from one is simple. It should show today’s times for exactly where I am, with the current prayer highlighted so I can see it at a glance. It should remind me when each prayer starts, so I don’t miss one. And it needs a widget on my home screen, because the whole point is not having to open an app to check.

It should also show Syuruk, sunrise, which is when the time for the dawn prayer, Subuh, runs out. Some mornings I pray Subuh late, and the first thing I need to know is whether I’ve still got time or already missed it. Surprisingly few apps show it.

That turns out to be surprisingly hard to find.

A lot of apps, and very few good ones

I’ve always used Android, and there’s no shortage of prayer times apps for it. But most of them have ads, a premium subscription, or a paywall for the features that matter. The free, ad-free ones often don’t work very well.

The most common problem is how they fetch the times. Many download a month’s timetable for one location, and then stop. If you travel, or the month rolls over, the times go stale until you remember to open the app and make it update, which rather defeats the point of a widget. And most apps only know about Malaysia, using the official timetable from JAKIM, Malaysia’s Islamic development department. Cross the border and you’re on your own.

In all my years of looking, I found two apps that I thought were genuinely good. The one I settled on was iSolat, published under the name MKMN, with its support pages hosted at Universiti Sains Malaysia. It was free, it had no ads, and it did nearly everything well enough. It had been downloaded around 380,000 times.

New Year’s Day

When 2024 arrived, iSolat stopped working. The new year’s prayer times simply weren’t there, and it wouldn’t download them.

I emailed the address in the app to report it. The reply came almost immediately:

Assalamualaikum, Developer asal app ini telah meninggal dunia pada 26.9.2023 lepas…

The original developer of this app passed away on 26 September 2023. The reply went on to say that USM had taken the app over, and would update it soon.

I was devastated. For more than three months after their death, their app had carried on quietly reminding its users when to pray, right up until the day the data ran out.

I wrote back to send my condolences to the developer’s family, and to thank USM for keeping the app going. I’m a backend developer, so I offered to help if they needed it. A little later, the maintenance was done and the prayer times were back. iSolat lives on, looked after by USM.

Al-Fatihah.

Following in their steps

That email stayed with me. I found myself wanting to do what they had done: to build something useful, give it away, and keep it going.

I had my own list of what it should be:

• Simple. Today’s times, all seven of them including Syuruk, the current one in bold, and nothing else in the way.
• No ads, and free.
• Private. Some prayer apps send your GPS location to a server to work out which timetable you need. I didn’t want mine to send anyone’s location anywhere.
• Not just Malaysia. It should keep working when you travel.

I was also curious whether modern React Native, the same framework I’d used to build an app for my kids, could handle the things a prayer app has to get right in the background: widgets that update on their own, and notifications that fire on time.

I started simplesolat in July 2025. The home screen widget went in within the first couple of days, and prayer notifications a few days after that.

Standing on others’ work

I didn’t start from nothing. A developer named Fareez Iqmal had built a similar app, and I first tried using the prayer times API he’d made. His approach to zones inspired mine, too. Each country’s official timetable is published per zone, a group of districts that share the same times. His backend used GeoJSON, a standard format for shapes on a map, to describe where each zone’s boundaries lie, and to find which zone a location falls in.

I thought about a simpler approach first: pick whichever zone’s centre is closest to you. But zones aren’t circles, and near a border, the closest centre can easily be the wrong zone. Real boundaries were better.

The difference in simplesolat is where that happens. Instead of sending your location to a server to look up, the app does it on your phone. It downloads the GeoJSON boundaries once, keeps them, and checks your location against them locally. Your location never leaves the device. All it ever asks a server for is the timetable for a zone.

The first version got its timetables from an API I wrote myself, in Rust. Later I realised I didn’t need an API at all, only static files that anyone could download. That turned out to be simpler, cheaper, and even more private. It’s also how simplesolat came to support official timetables for nine countries. That’s the next post in this series.

Looking back

I still think about that reply. Someone built a small, free, useful thing, and it went on helping people after they were gone. I don’t know if simplesolat will ever reach as many people as their app did. But if it helps someone not miss a prayer, on a trip, or on the first day of a new month, then I’m following in their steps the best way I know how.

simplesolat is free, with no ads, on Google Play, and the code is on GitHub.