Amazon, long rumored to be developing its own smartphone, is working on a screen that allows people to see 3D images without glasses, the Wall Street Journal reported Thursday. The Journal said the Internet retail giant is working on several gadgets to add to its offerings of Kindle tablets and e-readers. The report, citing people familiar with Amazon\'s plans, said the devices include two smartphones and an audio-only streaming device. The 3D screen would use retina-tracking technology, allowing images on the smartphone to seem to float above the screen like a hologram and appear three-dimensional. Speculation about Amazon smartphones has been circulating since 2011. At that time Citigroup said in a research note it believed an Amazon smartphone was in the works for the following year. The Journal said Amazon is making a broader push into hardware but still could defer the plans for financial or performance reasons.