Foxyapps.co was originally built in Sapper, but since SvelteKit is in public beta now, I've decided to upgrade. And so far I really like it, especially in terms of other integrations.
SvelteKit has adders that can add an integration with one command. I remember it was a struggle to add Tailwind to Sapper.
I'm really excited about the whole Svelte ecosystem and where it's heading. What about you?