There's a coffee shop/cafe on site. Free breakfast is available daily. Public spaces have free WiFi. Tarawanda House By Stawi also features a picnic area, coffee/tea in a common area, and concierge services.
This 3-star Zanzibar Town bed & breakfast is smoke free.
In Stone Town, but away from the hustle and bustle
Difficult to find, but once you do find it you'll be pleasantly surprised. Staff are nice and helpful, there's a nice garden-type atmosphere in the common area, and the room was clean and spotless. Breakfast was quite delicious, with a general mix of an omlette, crepes, fruit and/or vegetables; it does change if you stay more than a day. A nice place to stay if you can work remote. No TVs in the rooms for those who care.