💯 yes to both, we had lots of these in Solid, per event apps, and small micro apps that would do something small.  I had a go back in the day at some components:

https://nostr-components.github.io/event/

And small apps like:

https://nostrapps.github.io/taproot/

You can build lots of things like this quite quickly, but it's not yet taken off on nostr.