Why Ad-Deen is offline-first

A prayer time app that needs a network connection fails exactly when you need it most — on a train, in a basement, travelling abroad without data, or on a patchy connection at the masjid.

So Ad-Deen computes everything it can on your device.

What that means in practice

Prayer times are calculated, not fetched. Given your coordinates, the date, and a calculation method, the times follow from astronomy — no server involved. The Qibla direction is the same: a great-circle bearing from where you are to Makkah.

The Qur'an text, the du'a collection and the hadith database ship inside the app. The only thing that needs a connection is downloading recitation audio, and once downloaded it plays offline too.

The trade-off

Shipping data on-device makes the install larger than a thin client would be. We think that's the right trade: you pay the cost once, at install, instead of every time you open the app — and the app keeps working when the connection doesn't.

No ads, no tracking

There's a second reason for this design. An app that doesn't call home has very little opportunity to track you. No analytics SDK, no ad network, no account. Your location never leaves your phone.