Electronic paper (or e-paper) is a collective name for display technologies that offer paper-like performance - high display clarity and sunlight readability, and all that with very low power consumption (usually ePaper displays do not require any power while the image is not changing).
ePaper displays are found in many devices (most people will associate ePaper displays with e-readers such as Amazon's Kindle). ePaper displays are slowly entering the consumer mobile phone market.
Some phone makers are adopting ePaper displays in both smartphones (usually as a second display) or feature phones. ePaper displays can be used to extend battery lifetime, increase readability and also down-feature your phone - as some people prefer phones with less distractions and less features.
HiSense's A5C is an Android smartphone with a 5.84" 1440×720 (278 PPI) color E Ink display. This is the world's first color E Ink smartphone. Other specifications include a Snapdragon 439 chipset, 4GB of RAM, 64 GB of storage and a 4,000 mAh battery that can last up to 62 hours of continuous reading.
NTT DoCoMo's Card Keitai is the company's lightest phone ever at only 47 grams, and it features a single 600x480 E Ink display. It's a feature phone (cannot add applications) that supports simple functions.
The Card Keitai will ship in Japan by the end of November 2018 for around $280.
The HiSense A6 is a dual-screen smartphone that features a 6.1" 2160×1080 AMOLED display on the front and a 5.6" touch E Ink Carta HD screen on the back. Other features include a snapdragon 660 chip-set, 6 GB of RAM, 64/128 GB of storage and a dual-sensor 12Mp camera. The E Ink display can mirror the front display, which can then be used to run an e-reader application or any other application.
The Light Phone 2 is a simple 4G (LTE) phone that is based on a large E Ink display. The Light phone 2 is based on the company's own OS and supports messaging, phone calls and more simple functions.
The Light Phone 2 was funded in a crowdfunding campaign (which reached its goals very quickly). The phone will cost $225 as part of the campaign, with a $400 target retail cost. It will ship by April 2019.
The Hisense A2 Pro is a dual-display Android smartphone that features a 5.2-inch 960x540 E Ink display on the back. The front (and main) display is a 5.5-inch FHD OLED display. Other features include an octa-core Qualcomm Snapdragon 625 chipset, 4GB of RAM, 64 GB of storage, microSD slot, 12 MP camera and Dual-SIM.
The Hisense A2 Pro will launch soon in China, pricing information is not available yet.
The YotaPhone 3 is the 3rd-generation dual-screen smartphone. The YP3 features a 5.2" E Ink display on the back and a 5.5" FHD AMOLED as the main display. Other features include a Snapdragon 625 CPU, 4GB of RAM, 64/128 GB of storage and a 13MP camera.
YotaPhone will start accepting pre-orders in early September 2017, with the 64GB priced at around $350.
HiSense's A2 is a dual-screen smartphone that features a 5.5" FHD AMOLED screen on the front and a 5.2" 960x540 E Ink screen on the back side. Other features include Android 6.0, 1.4Ghz octa-core CPU, 3/4GB of RAM, 32/64 GB of storage, finger print sensor, a microSD slot and Dual-SIM.
The A2 was launched in January 2017, but HiSense did not yet reveal the release date or price of this new phone.
The Flag D1 is a dual-screen Android (v5.1) smartphone that features a 5" 720 IPS front display and a 4.7" 960x540 E Ink back display. Other features include a quad-core 64bit CPU, 2GB of RAM, 16GB of storage, microSD slot and a 8MP camera.