FBReader is a cool app released for Android mobile devices, which can be used each time you want to read ebooks on your phone/tablet. This one comes with support for main electronic book formats like fb2, ePub, azw3, and even HTML, RTF, TXT, and DOC. The user interface is very intuitive, allowing you to manage and access your entire ebook collection.
You can also use the integrated search function when you are interested in finding a specific title. When it comes to the reading environment, you will be happy to know that you are permitted to pick a different text font, adjust the screen brightness by sliding your finger up or down along the left edge of the screen, use custom backgrounds, etc.
Another positive aspect of FBReader is the ability to use the built-in browser/downloader to gain access to various ebook catalogs and stores. You also have the standard option of downloading ebooks by yourself and placing them inside the "/sdcard/Books" folder. This reader also has support for synchronization of your reading positions and ebook library with Google Drive.