The Apple Support app has been updated to version 4.0 and now has dark mode, an updated user interface, and offers support for Apple services and subscriptions (via 9to5Mac).
In a few minutes of playing around with it, the updated app has been pretty easy to navigate, and the dark mode looks good, in my opinion. Here are some screenshots of what the new interface looks like, with dark mode turned on:
And here are the full patch notes for version 4.0, from Apple:
Apple introduced the Apple Support app in the US in December 2016 as a dedicated support hub for your Apple products and as a place to let you discuss and schedule repairs for your products with Apple. You can download the Apple Support app from the App Store for free.