Sony's Xperia M4 Aqua is full-featured, waterproof and affordable

Well-equipped smartphones that cost US$300 or less is one of the big trends at this year's Mobile World Congress, and Sony wants in on the action. Last week it launched the Xperia E4g and on Monday it announced the Xperia M4 Aqua.

The smartphone will cost about '300 (US$335) when it goes on sale during the second quarter in 80 countries. It has a 5-inch, 720 x 1280 pixel screen and is powered by Qualcomm's Snapdragon 615, an octa-core processor with integrated support for LTE. The processor is a step below the Qualcomm's Snapdragon 800 family, which is used to power high-end smartphones.

The M4 also has a 13-megapixel camera on the back and a 5-megapixel camera on the front. The camera on the front builds on the selfie-friendly trend that took off last year, and has a wide-angle lens with an 88 degrees field of view.

Sony is also boasting about the M4's battery life, which is increased by the processor and Sony's own Stamina and Ultra Stamina modes. The company promises a two-day long battery life, but doesn't elaborate on how much the phone can be used and still last that long.

On the software side, the M4 is running Android Lollipop, and Sony has adopted Google's material design for the company's additions to the operating system's user interface, it said.

But even if Sony has put together a promising product, success is far from certain. There are multiple other products to choose from that have similar specifications, including HTC's Desire 820 and ZTE's Blade S6, which are also powered by the Snapdragon 615 processor.