Do You Know This Plant?

There is a tree on our backyard on the river side that blooms and bear fruits; but its fruits is just wasted away because no one eats it.

I thought if this tree or its fruits are not meant to be eaten so why they bear fruits if its fruits are not a food or they belong to plants or trees whose fruits is inedible?Perhaps as some says there are fruit bearing trees whose fruits is inedible.But I am still curious of what this tree is.

Some in our area called it "Bangle"; but I am still in doubt thus I am asking if you know this tree? or this plant?

There are some of them that sprouted on our backyard.