Oaxis has been selling secondary e-ink screens for Android and iOS phones for a number of years. The screens are built into a dedicated case, which protects your device from the rigors of daily life. Oaxis released the InkCase i7 a few months ago for the iPhone 7 and this is likely their best product yet.
The InkCase i7 features a 4.2 inch e-ink screen with a resolution of 480 by 800 and 217 PPI. This device hooks up to your iPhone via Bluetooth and is good for about a month before you have to hook it up to the proprietary magnetic charger.
It is important to note that the e-ink screen does not mirror what is displayed on your iPhone. You need to download dedicated apps the Apple App Store, including one that will read e-books and another that will display your photos as a slideshow.
Michael Kozlowski is the Editor in Chief of Good e-Reader. He has been writing about audiobooks and e-readers for the past ten years. His articles have been picked up by major and local news sources and websites such as the CBC, CNET, Engadget, Huffington Post and the New York Times.