We have an apple tree about 15 years old, inherited when we bought the house. It has brown spots and rotting fruit early in the season and some leaves are browning at the edges.
Apple Tree With Brown Spots
Certified GKH Gardening Expert
I'm sorry your Apple tree isn't doing well!
It sounds like your tree may be suffering from Black Rot. It's caused by a fungus.
There are other possibilities, though. These articles will help you identify and correct whatever is ailing your tree: