Given their Siri issues...
... I suspect a substantial chunk of cash will be spent on building more data-centres.
Philanthropic gestures are what businesses do to reduce their tax bills. It has bugger all to do with being nice to others and everything to do with getting away with paying as little tax to the government as they can get away with—a policy generally enforced by shareholders of every major corporation. So, don't expect a "Jobs Foundation".
Besides, charity is not a panacea: it's been 28 years since "Band Aid" and Ethiopia still has trouble feeding itself. You need viable societies first and foremost, but many African nations are still riven by tribal conflicts. You can't just buy a new society. The will has to come from within, not be imposed from without, or you just end up with a nation of willing victims who grow up to expect the West to intervene whenever they make mistakes.
(Personally, I'd only ever give money to organisations involved in education, or information dissemination. New schools, infrastructure and supplies for same, independent journalism, etc. If we want to "spread Democracy", we need to remember that a democracy requires an educated and well-informed population. Neither is an optional extra.)
Paying dividends may be a possibility, but seems unlikely given that Silicon Valley have never been keen on that. Apple are far from the only ones; Microsoft also never paid dividends while Bill Gates was in charge.
Gates is often credited with starting this trend. The problem with this approach is that there's little incentive to keep the shares for a while and take a long-term view; you lose the interest of people who actually have a clue about what it is the company does and who could therefore spot management bullshit a mile away. Today's shareholders only ever take the short-term view: "Fatten the goose, so I can sell my shares on at a profit!" Shares have become surrogates for money. Nothing more.