Atis (sugar apple)

"Known internationally as sweetsop, sugar apple or custard apple, the Atis is one fruit you can easily grow even if you have only a square meter of soil. The atis tree grow just about anywhere a seed falls. And it grows fast so that you can get to harvest fruits in a little over a year from seedling stage. A tree bears fruits about three times a year: in the summer, during rainy season and towards Christmas. The best batch of fruits, those with thicker and sweeter flesh, comes out in the summer."http://www.seasite.niu.edu/Tagalog/Tagalog_Default_files/Philippine_Culture/pagkaing%20pilipino/philippine_fruits.htm