Samsung (NASDAQOTH: SSNLF) owns Android. Until very recently, it was the only Android handset maker actually making money off its devices; even now, it's the only one that's wildly profitable. According to OpenSignal, about half the Android phones in existence are Samsung-made.

But that could change. A host of competitors, companies like Sony (SONY -0.46%), Lenovo (LNVGY -0.27%) and Google (GOOGL -0.09%) itself, are coming after the Korean tech giant.

Sony aims for the high-end
Sony's been making Android phones for a few years now, but it wasn't until 2013 that the company finally broke through. Sony's last earnings report revealed a surprising profit at its mobile division.

Back in January, Sony's CEO laid out his company's plans: Focus on the high-end of the market and sell phones with large margins that can drive profit. So far, he's done just that, and Sony's rolled out several high-end smartphones in 2013.

These include the Xperia Z, the Xperia Z1, and Sony's new phablet, the Xperia Z Ultra. Alongside these devices, Sony has launched the Xperia Z tablet, the lightest, thinnest, and only waterproof tablet on the market. Sony will also sell a smartwatch alongside Samsung this fall; its SmartWatch 2 has less features than Samsung's Galaxy Gear, but is $40 cheaper and can work with nearly any Android phone.

Lenovo looks to do to smartphones what it did to PCs
Lenovo is one of the world's largest PC OEMs. It wants to extend that dominance to the mobile world, and so far, it's right on schedule. Back in August, Lenovo said it shipped more mobile devices than PCs, particularly impressive given that the company is a newcomer to the market, and also, that nearly all of its sales have come from China.

But Lenovo wants to bring its phones to the West. Back in May, Lenovo's CEO told The Wall Street Journal that his company wants to sell phones in the US within one year. That doesn't seem unreasonable, and given Lenovo's strong lineup of phones, the PC giant could do well in the US. Lenovo's flagship Android handset, the K900, is on par with other top-tier Android handsets, including Samsung's Galaxy S4.

Of course, Lenovo isn't the only Chinese handset maker that has its sights set on the US. Xiaomi, a company some call the "Apple of China," just hired Google's Hugo Barra to lead its international expansion plans. That could mean Xiaomi-made Android smartphones available for sale in Western markets in the not-too-distant future.

Motorola's Moto X could set sales records in the US
Then there's Google's own in-house hardware unit, Motorola. Its new phone, the Moto X, doesn't win any awards when it comes to internal hardware, but the phone has received favorable reviews, and should sell exceptionally well this fall.

In era when smartphones are starting to become indistinguishable, the Moto X offers something remarkably unique: the ability to customize the phone. Using Motorola's website, a would-be buyer can design their phone's look, then have it shipped directly to them.

In order to accomplish this feat, Motorola has to manufacture the devices in Texas. Google has already played up this "made-in-America" notion in its advertising, and that makes sense -- the phone should be widely popular with the "buy American" crowd.

Longer-term, Motorola could be expected to produce other great Android handsets. Safely underneath the Google umbrella, Motorola can afford to experiment. These moonshot bets (as the company's management has called them) could pay off big time.

Android competition heating up
Looking at the Android market as its stands today, it's easy to declare it a one-horse race. Samsung is king, and everyone else is fighting for scraps.

But there's no guarantee that will continue; indeed, it seems unlikely. After years of mediocrity, both Sony and Motorola appear to have woken up, ready to challenge Samsung with a number of impressive new devices. Longer-term, rising Chinese tech stars like Lenovo, wildly successful in their home country, seem poised to bring their devices to foreign markets.

That competition should be fantastic for the consumer; it may not be so great for Samsung.