Apple profits have risen again, thanks to strong iPhone sales in China. The company has been doing an excellent job with its devices, but as it stands right now, the iPhone is the only device that is contributing significantly to Apple's growth.

CEO Tim Cook refuses to go into detail during a company earnings conference call on how Apple will keep going upwards in 2016. So now the big question is, how can Apple keep the growth streak alive? 

At the moment, however, that doesn't matter as Apple managed to post a profit of $11.1 billion for the fourth quarter, up by 31 percent when compared to the same time back in 2014. Revenue climbed to $51.5 billion, which is up by 22 percent compared to the year before. The results here exceeded what Wall Street had expected. The company's forecast revenue is between $75.5 billion and $77.5 billion.

Apple also states that it has sold 48 million iPhones, which is a decent growth over the 39 million sold during the same period in 2014.

When it came down to the Apple Watch, however, the company remained a bit cagey on the details. However, according to a report from Bloomberg, analysts believe Apple only managed to sell around 3.8 million units of its smartwatch. That's not a huge number, but better than what other companies are doing right now.

Mac sales also increased to 5.71 million compared to the 5.6 million a year before. A small increase, but still enough to put pressure on Windows hardware manufacturers.

One of the main reason for Apple's success this quarter has a lot to do with China, and it is expected the company might have better success in the months to come after its plans to increase the amount of stores in the country from 25 to 40 by the end of the year.

According to Reuters, analysts believe China will replace the United States as Apple's biggest market, but they have failed to give a time frame on when this could happen.

Photo: Kārlis Dambrāns | Flickr