It's a light novel reader, currently in beta.
Requirements:
Android Kitkat (4.4) or higher.
Google Play Services (downloadable fonts).
Download link: Ranobe
Create an issue: Bitbucket
Reddit: r/Ranobe
Changelog (20180405):
New option: full screen.
Button in the list of chapters to resume your reading.
Restore the state of the application has been improved on Nougat and higher.