**Editor's Note: Click here for our ranking of March's hottest selling smartphones to see how Apple's iPhone and the Samsung Galaxy S4 fared against the competition.**
It looks like Apple's iPhone 6 won't be the only serious competition this year for the just-released Samsung Galaxy S5.
Speculation has run rampant for years that online retail giant Amazon.com would unveil its own smartphone to challenge the biggest players in the handset market. After all, Amazon started selling its Kindle Fire tablet PC a couple of years ago, with some pretty decent success.
The closest thing to an outright guarantee came on Friday from the Wall Street Journal, whose sources (people "briefed on the company's plans") said that Amazon has been showing off the technology to developers in Seattle and San Francisco over the past few weeks. Look for an announcement in late June, with a release date sometime in September, those same sources said.
So what will differentiate an Amazon handset from any other smartphone out there? The WSJ's sources say it'll be a display that's capable of showing "seemingly three-dimensional images without special glasses." The phone also will supposedly offer technology that tracks your retina in a series of front-facing sensors, capable of making some images 3-D-like, much like a hologram.
No word yet on a price, but the technology involved would certainly make it one of the more expensive devices on the market. Which wireless carriers might sell it? Mum's the word so far, and Amazon refused to comment on the story as well.
Follow senior online managing editor @Craig_Galbraith on Twitter.