The Granny Smith apple is widely known for its bright green color.  The skin of this apple is tough and the flesh is crisp, bright white in color and resists browning.  Its flavor is acidic and tart but tends to sweeten over time in storage.  Granny Smith apples store well for very long periods of time, up to a year if refrigerated just above freezing.  Commonly used for baking and in salads, this apple can also be eaten fresh.  

Your Granny Smith apple tree is in flowering group 3. It is self-fertile and does not need a  pollination partner, but fruiting will usually be improved if there is a compatible partner of a different variety nearby.