Source: Apple.

Apple (NASDAQ:AAPL) announced earnings for the fourth quarter of fiscal 2015 on Tuesday, Oct. 27, after official market hours. While the report didn't offer much in terms of big surprises, the business continues performing remarkably well on the back of strong iPhone sales, avid demand from China, and expanding profitability.

The iPhone is still on fire
Total revenue during the quarter came in at $51.5 billion, a 22% year-over-year increase from $42.1 billion in the fourth quarter of 2014. Management was expecting sales in the range of $49 billion to $51 billion during the quarter, so performance was above the company's own guidance.

The iPhone segment continues firing on all cylinders. Apple sold 48 billion devices during the quarter, a 22% annual increase. Average selling prices have been on the rise in the iPhone segment over the past several quarters, and the September quarter was no exception: Apple registered an average selling price of $670 during the period, an increase from $660 in the third quarter of fiscal 2015. 

Because of rising average selling prices in the iPhone division, revenue growth was above unit sales growth during the quarter, Apple brought in $32.2 billion in sales from the iPhone segment, a 36% jump from the same period last year.

Apple made a big 63% of total revenue from the iPhone during the period. The good news is that the product keeps selling notoriously well, and this is generating extraordinary financial performance for Apple. On the other hand, Apple is remarkably dependent on the iPhone, and this is an important risk factor to keep in mind.

iPad sales, on the other hand, continue declining. The company made $4.3 billion in revenue from the iPad segment last quarter, a 20% contraction from $5.3 billion in the same quarter last year. Mac sales grew 4% year over year to $6.9 billion. Sales in the services segment increased 10% to $5.1 billion, while other products, which includes Apple TV, Apple Watch, and Beats products, among others, grew 61% to $3 billion.

Investors have been particularly concerned about the situation in China lately, since the Chinese economy is showing some worrisome signs, such as slowing growth and financial instability. Still, Apple reported a strong 99% increase in revenue from the Greater China region, amounting to $12.5 billion during the quarter.

Strong earnings and cash flow
Gross margin was 39.9% during the period, a 38% increase from the same quarter last year. Guidance was for gross margin to be between 38.5% and 39.5%, so the business did better than expected on the margin front, too.

Apple is a cash flow-producing machine. The company brought in $13.5 billion in operating cash flow during the quarter, and it returned over $17 billion to investors via dividends and buybacks. Apple has now completed over $143 billion of its $200 billion capital return program. Earnings per share, meanwhile, grew by a vigorous 38%, from $1.42 to $1.96 per share. 

The future looks good
CEO Tim Cook sounded quite optimistic about the company's prospects over the coming quarter, which is particularly important for Apple since it includes the crucial holiday shopping season. Cook said in the press release:

Fiscal 2015 was Apple's most successful year ever, with revenue growing 28% to nearly $234 billion. This continued success is the result of our commitment to making the best, most innovative products on earth, and it's a testament to the tremendous execution by our teams. We are heading into the holidays with our strongest product lineup yet, including iPhone 6s and iPhone 6s Plus, Apple Watch with an expanded lineup of cases and bands, the new iPad Pro and the all-new Apple TV, which begins shipping this week.

The company is expecting revenue in the range of $75.5 billion to $77.5 billion during the December quarter. This would represent a slight increase from $74.6 billion during the same quarter last year. Gross margin is forecast to be between 39% and 40%, roughly in line with 40% of revenue during the December quarter in 2014.

While this doesn't sound like a very optimistic forecast, it's important to keep in mind that foreign currency depreciations are hurting most companies in the tech business when translating their financials to U.S. dollars. Besides, Apple is traditionally known for being conservative when it comes to guidance. 

The latest earnings report from Apple didn't bring many big surprises, but the company keeps delivering healthy sales figures and rock-solid profitability, so things seem to be going in the right direction for investors in Apple stock.

Andrés Cardenal owns shares of Apple. The Motley Fool owns shares of and recommends Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.