This follows through into the app, which itself is a good demonstration for how a developer can tightly follow design guidelines while extended them with their

This follows through into the app, which itself is a good demonstration for how a developer can tightly follow design guidelines while extended them with their own originality. This is generally a good thing for users - building a unique UX for every app doesn't service the user. Some naively believe this is vanity, but no single app lives in isolation, so having all apps generally act and function similarly makes it very easy to pick up a new app and hit the ground running. Yes it also looks nice when all the apps look like they're from the same package, but that's not why we do it. Something that stuck with me in the 90s was this description of the mac experience: "when you've learned one app, you've learned 80% of another". I bought Pixelmator and started using it immediately without any reference material, tutorials or videos, it is a 10/10 in quality software development.