The fruit (not the computer) is traditionally a symbol of love.
(although i suppose putting up with a SO's apple computer habit while one is a pc user is *also* a symbol of love)
But both in mythology and "herbology" (althogh plant lore is the better phrase here) the apple fruit stands for love. An apple bough hung above a doorframe is supposed to bring peace and love into a house and bless the couple.

A very simple love spell that is supposed to strengthen the bond between a couple is this: (NOTE: it must be done between a pre-existing couple or two people who *want* to be a couple and both parties must know its intent, or this enters the VERY dangerous realm of manipulative magic)
Take a red apple (any variety) and cut it in half *crosswise*--aka not from top to bottom but across the width of the apple. This leaves two halves of the apple, each with a star formed in the center by the seed (symbolically a pentagram/pentacle). Each partner should eat half this apple, or better and stronger and more powerful feed the half to the other.