Amazon Kindle tablets have grown in popularity due to competitive pricing and the Amazon content eco-system. It appears that Amazon is working on a Kindle phone and if it's priced right, could be a great choice vs the Nexus 4 for a cheap unlocked phone with great specs.
DigiTimes reported that Amazon is developing a 4.7" inch smartphone. Today's rumor from the Wall Street Journal is that Amazon is working on many devices, including media-streaming/players and smartphones. One smartphone may have a glasses-free 3D screen that makes images appear to floating above the screen and menu navigation using eye tracking. Processors for LTE enabled devices would be made by Qualcomm.
Two smartphones are reportedly being developed on the Amazon Lab 126 Cupertino campus. Amazon may also be working on a media streaming device for videos. The devices are in the development phases and may or may not ever come to mark. although no pricing was confirmed, Amazon has been pricing its devices at near cost and profiting from content and sales on Amazon.com
Other previous rumors suggested a June release of a Kindle phone which do not make since Amazon always introduces its brand new devices in time for the holiday buying season. Meanwhile Amazon has reduced the price of the Kindle Fire HD for Mother's Day down to below what it costs to make.