Are there any duty-free shops in Zanzibar Island, Tanzania?

Yes, Zanzibar Island is part of the United Republic of Tanzania. There are duty-free shops on the island, but there are few brands. It is divided into two main islands, one in the south and one in the north: Unguja Island and Pemba Island, as well as about twenty other small islands, the capital of the two islands, Zanzibar City, is located on the west side of Unguja Island.