Smartphone makers shipped a record 1.4 billion devices in 2015

But they experienced the slowest growth rate ever in the fourth quarter.

Smartphone global shipments grew 12 percent and hit a record 1.4 billion devices in 2015, according to Strategy Analytics. That doesn't mean all's well in the industry, though -- not when it's no longer expanding as fast as it did in the past. In the fourth quarter of 2015, shipments grew merely six percent from the same period in 2015. The research company says that's the industry's slowest growth rate of all time, most likely because the people in major markets like China who are inclined to use smartphones already have one.

Samsung, however, continues to thrive and lead the pack. It shipped 81.3 million units worldwide in the fourth quarter, up nine percent (its highest within the past two years) from Q4 2014. Apple, on the other hand, isn't doing too hot. It still shipped 74.8 million iPhones in Q4, but that's barely higher than the 74.5 million devices it sent out in 2014. Strategy Analytics says "Apple's iPhone growth is peaking," and that Cupertino should look into exploring new markets like India to ensure it doesn't remain stagnant.

Huawei's two percent growth from 2014 is nothing to write home about either, but it still comes third after the two clashing giants. Xiaomi in fifth place shipped over 2 million phones more compared to 2014's figures. It seems the only entry in the top five that shipped fewer units in 2015 is Lenovo-Motorola, whose growth rate has declined by 18 percent.