Apple Inc's latest iPhone went on sale in stores across the globe on Friday, October 14, with fans snapping up the final gadget unveiled during Steve Jobs' lifetime, many buying the phone as a tribute to the former Apple boss.

Hundreds queued around city blocks in Sydney and Tokyo to be the first to get their hands on the iPhone 4S, which looks similar to the previous iPhone 4 but has a better camera, faster processor and well-received voice activated software, Reuters reported.

Apple CEO Tim Cook and his executive team hope the first device launched without the firm's former visionary leader at the helm will safeguard their global market share against a growing challenge from the likes of Samsung.

The iPhone - seen as the market's gold standard - is Apple's highest-margin product and accounts for 40 percent of its annual revenue. It is the world's biggest selling smartphone, with a slim market-share lead over Samsung.