Jazm is a free macOS menu bar app that helps you stop missing prayers because you're absorbed in work. At each of the five daily prayer times, it shows a warning banner and then a short countdown, and then it locks your Mac. That puts the screen out of the way so you can go pray, ideally in jamaat at the masjid. When you unlock, Jazm asks whether you've prayed. It's free for the Ummah.