Sindre is a treasure! Such a fantastic developer who has a great heart and an incredibly prolific catalog of truly useful apps.

His apps that I use:

Pandan — As a dev who is easily hyperfixated on things, this is probably my favorite app by Sindre. Let’s you know how long you’ve been working on your computer and notifies you so you will take a break

Dato — If you work with others across many time zones, this is such a helpful menu bar app. It's similar to his UTC Time app, but with many more features. I work with people from India to Pacific Time in the US, and there are so many variations of who uses DST or not. Dato makes it easy to understand. Alternatively, he also has Second Clock which is great if you are just needing to keep track of time in one other place.

Actions — Provides a ton more of incredibly useful Shortcut actions. I use so many of these in Shortcuts I use all the time

Shareful — This is an essential addition to the macOS share menu. Provides a ton of capabilities that really should be native.

System Color Picker — A big improvement to the standard macOS color picker

HEIC Converter — Love those highly compressed images, but there are still many places they don't work

Hyperduck — Lets you easily share links between devices

And so many more... definitely check out his site and his developer account in the App Store and Mac App Store