There are multiple word lists in use in Crossword Island Hopper and Bog Gobbler:

The
NASPA Word List 2023 Edition © NASPA 2023. The copy
included in this game is licensed for personal use. You may not use it for any
commercial purposes.
The Collins 2024 Word List (CSW 2024). Published under licence from Collins, an imprint of HarperCollins
Publishers Limited.