I just bought the inkbook obsidian.
I can't answer your questions about the build in readers. When I tried both of them I didn't see any option to change to night mode (light on dark background), so I tried other reading apps from the app store. So far my favorite on the device is Bookari. With it (and a few others that I tried) I can toggle between night and day mode.
But I didn't find any other way to toggle the light on/off other than thru the menu.
I also was able to add the Pocket App to read web pages offline.
Overall I like this ereader
|