It's on an island called Boilangga in the Togean Islands in Indonesia (Sulawesi) not Thailand. I stayed on a neighbouring island at Fadhila Cottages. Fadhila Cottages, Togean, Sulawesi

Not very easy to get to so I doubt if it will be invaded by mass tourism in the foreseeable future!

A request to anyone who does go to Fadhila cottages .... take medicines with you to give to the owner for redistribution to the local villagers. They have no doctor or pharmacy there and it's twelve hours from mainland Sulawesi (only one boat a week). They are short of everything, even aspirin but they particularly need antibiotics and antimalarials ....especially meds with dosages suitable for children and babies.