George Orwell's 1984 - other books set in this universe?

1984 remains a significant work of speculative fiction, and offers a sketchy but powerful portrait of a totalitarian world.

Have others set novels / movies specifically within the 1984 universe? I expect there have been lots of borrowings of elements of the story, but any actually set in or building on what Orwell depicted?

That would be double-plus good.

1985 - The Death of Big Brother

Maybe not what you’re looking for, but the forerunner of 1984 is We, by Yevgeny Zamiatin:

From the item:

I dunno. Having read both 1984 and We, I find the latter much more disturbing than 1984.

There’s this one, which rewrites the book to set it ten years later, in which the author argues that the rise of the internet will put an end to totalitarianism. (Not looking like such a good call in retrospect.)