After losing significant ground in the top-end smartphone market with the iPhone 5, many asked if the magic was gone around Apple HQ - and if Tim Cook would be able to keep the company ahead of its rivals for much longer.
Then came the iPhone 6 - a product that took the company to a new level. In February of this year Apple hit a market valuation of $710bn. That's twice the market value of Google - and eight times the size of McDonald's.
In the year to date Apple has generated revenues of more than $123bn - and 68% of this money has come from iPhone 6 sales.
Tonight the company is expected to launch the iPhone 6s and the iPhone 6s Plus - a mid-cycle release with a faster processor, and a better camera. Unlike the iPhone 5s - this is expected to be the new flagship model - and the price of the standard iPhone 6 is expected to drop in the coming weeks.
But early signs suggest that investor enthusiasm could be on the wane - Apple shares are down by 6.2% over the 30 days leading up to the launch.
Apple shares have fallen from their July peak
This is down from an average of a 5% bump in the company's share price in the weeks leading up to previous iPhone launch events.
Some 75% of iPhone users are yet to upgrade to the large-screen sixth generation of the phone - leaving plenty of room for growth.
The company already sold 75 million iPhones in the first quarter of its fiscal year, and 47.5 million in its third quarter which ended on June 28th.
This far into the lifecycle of the iPhone 6 investors will be wondering where the company's next innovation will come from - especially as the gap shortens between Apple's smartphones and cheaper alternatives.
Apple will also launch a new third generation Apple TV this evening- and a new large iPad aimed at professionals, as well as a new suite of Apple Watch apps.
As ever, there will probably be some surprises - we are expecting an Apple Music update, new phone and computer operating systems, and a new iPad mini-model.
The launch event takes place in California at 6:00pm GMT.
