I loved reading my ebook files on Android devices using ReadEra. However, once I got an iPhone I felt the need to have a similar ebook reader that worked and synced across both my iOS and Android devices. Thankfully, I found a near-perfect solution in eBoox.
It supports epub files, which is what I typically read. But also supports a ton of formats like fb2, doc, zip, rar, cbr, cbz, html, rtf, txt, docx and odt. Note the absence of PDF though.
It has the must-have feature I need - synchronization between iOS/Android devices using my Google Drive account. It can download books and sync the quotes and bookmarks. Sync is not perfect, I have found that I need to manually choose sync on one device and then manually choose sync on the next device.
Press in the middle of the screen to get access to the bookmark button (top-right or bottom-righ corner) and the settings.
The settings UI is very modern, but once I figured it out it was fine to use. I can change the font, line spacing, margins, brightness, foreground-background color theme, orientation, page change animation, page change with buttons and word wrap.
Press and slide the book cover to the left to get the options to move or remove the book.
There is a colored tab on the left margin that moves down as you progress through the book and also changes color.
There is another progress indicator in page numbers or percent at the bottom of the page.
Selected text can only be copied, shared to another app or marked as a quote (in one of 3 colors). There is no option to lookup the selected text in a dictionary app. I am managing right now by copying the word and then pasting it into WordWeb app - not ideal.
Unlike ReadEra, adding books has to be done manually. There is no way to ask it to use a directory and show me all the books there. Similarly, there is no way to delete the book file from the app.
When I finish a book, it is automatically moved to the Finished shelf. I like this feature and I wish ReadEra had this.