It’s called custard apple, green when it’s ripe and turns to black when it’s too ripe. so u need to feel it to know if it’s ripe to be eaten. that’s when it’s soft. Sweet and lots of pips [big black hard pips]
Got a bit more info from wiki, custard-apple and sugar-apple is actually different. Both looks alike and belongs to the same species of Annona.
Can’t really determine that the Annona in my photo is a custard-apple or a sugar-apple (or possibly another type of Annona), the images resource online seems to mix these 2 up, and it looks way too similar for me.