So, here's information on the first five islands, and the names of the other five I haven't figured out details for. If you have ideas for details on the other five islands, PM me
Ranseki Island
Ranseki Island is the main island of the Archipelago and is where planes arrive to drop off new residents. Ranseki island is known for its grassy green plains and the refreshing summer breezes that always stay warm, even in the dead of winter. The island's native fruit it apples, and the soil is incredibly fertile for all sorts of flora.
Kakuni Island
Kakuni Island is the only island in the Archipelago that has a volcano. Of course, this volcano went extinct years ago, otherwise, Nook Co. would never allow it to be inhabited. The volcanic eruptions of the past show to this day, both with volcanic rock on the beaches, and ash covered trees. Even with all the ash, the soil and environment is perfect for the pineapple trees that grow on the island
Ula'Ula Island
Ula'Ula Island is the largest of the islands in the Archipelago and is known for its wheat fields, which are free for any residents to harvest for whatever purposes they wish. Besides the wheat, the island is also home to plum trees, and Nook Co. is planning on opening a bakery on Ula'Ula Island.
Sakurini Island
Sakurini Island is known for its fishing industry and many unique and colorful fish call the rivers and beaches of Sakurini Island their home. Along with fishing, there is a large cave that goes far below the sea level and gives residents the opportunity to feel like they're diving because of the solid crystal clear walls that nature formed over time. Mangoes are the native fruit of Sakurini Island.
Diareni Island
Diareni Island is a bug catcher's paradise, no matter what time of year it is, there are always bugs to catch day and night. Once in a while, this is the island that the Bug Catching Contest takes place on. The peach trees that grow on Diareni Island attract massive swarms of bees, so residents are asked to take care while harvesting fruit as to avoid being stung by bees.
Arakuna Island
Quele Island
Finiko Island
Pumari Island
Jakanuni Island