Helin is an amazing host!
The apartment is bright, stylish and very well thought out.
It is located in the district Bebek, which is a very nice place to stay if you are looking for calmness, good service and safety. There are a lot of different restaurants around. Trip to the Istanbul city centre takes around 15-20 minutes by taxi.
It was the 4th flat during our stay in Istanbul and definitely the best one. Highly recommended!