This tree is familiar, this is a Black Plum or Jambul fruit. My parents brought me this fruit and I tried eating It and It tastes sweet and a little bet of sour. No wonder birds likes to eat this fruit, because when this black plum fruit turns very ripe it tastes sweet sort of tasted like a ripe grape fruit. And also it will stain your tongue in purple color. I Love this fruit so much, I use to eat this fruit with soy sauce and vinegar with chilies, So good. Try it and leave me a reply if you like it or not. Thanks!