I eat the skin (when it is ripe) and the flesh too but the single seed which is in the centre is prickly and spiny. Usually I peel it though and then I do something that you might think strange, I add salt. Not all people do this but quite a few do and man it tastes good. The fruit as you can see is oblong and green when unripe. When it is ripe the inside is yellow like the skins and it has a tangy flavor but the riper it is the sweeter and to me the better the taste. Some people think its flavor is like a cross between a pineapple and a mango.
This tree bears its first fruit after about 2-4 years and after that gives a steady supply of fruits from the fall through the winter months. This fruit is inexpensive and plentiful in tropical countries especially in the Caribbean. Also like most it is good for you with its rich supply of vitamin C and iron. Many people like the juice which is now being marketed in attractive containers quite unlike when I was a child. Nobody could find that in the store and you would have to make your own.
In addition to eating it raw, some people like it stewed and for those who enjoy gourmet cuisine you can use it to make a glaze, sauce or chutney by adding vinegar, pepper and salt. If you live near an Asian or West Indian store, check it out. It is scrumptious!