The reason that gravity dominates the interaction between an apple and the Earth is that they are both electrically neutral, to a very high accuracy. In order for the electric force of repulsion between an apple and the Earth to be similar* to the gravitational force of attraction between them, only one atom in every 10^20 would have to lose an electron. We owe the downwards fall of the apple to the fact that matter is electrically neutral to an accuracy far better than 1 part in 10^20.
* Electric forces can be attractive or repulsive because objects can possess either positive or negative electric charge, and like charges repel whilst unlike charges attract. Gravitational forces are always attractive -- there is no such thing as a repulsive gravitational force.** The reason for this is that mass only comes in one form -- 'negative mass' and 'antigravity' remain in the realm of science fiction.
** Negative gravity is not a new idea. Albert Einstein himself first suggested the idea when he developed his general theory of relativity in 1915. Having derived the equations that describe the overall behaviour of the universe, Einstein was concerned that his equations did not allow a static universe to exist. According to the equations of general relativity, the universe has to be either expanding or contracting. At the time there was no evidence that the universe was anything but static, so Einstein introduced an extra term into his equations which he called Λ (capital Greek letter Lambda) -- the so called cosmological constant. This took the form of a sort of negative gravity and was assumed to be just strong enough to counteract the pull of gravity and so result in a static universe. When, a few years later, Edwin Hubble announced his evidence that the universe is in fact expanding and not static at all, Einstein is said to have commented that the introduction of the cosmological constant was the biggest blunder of his life. However, in the light of Type Ia Supernovae results, maybe Einstein was on the right track after all ...