I have already purchased some ebooks from Google Play store on my Nexus 7 and want to build up a digital library. When I open them within Google Books App, I note there is no section to organize, sort, or group books. The other Android Ebook Reader apps like Moon+ have the feature, but I can't find a way to import them or read e-library. How can I fix the issues?
The Google app lacks of organizing Books since now. Content providers, such as Google, Apple, Amazon, restrict the flexibility of your purchase and only allow you to use a single source of content, so you are unable to transfer from one content to another. However, Amazon is the best choice, because the app has many version for multiple platforms.