In order to find an ads free app, I will prefer to use F-Droid instead of Google Play.

Recently, I downloaded a PDF of Stubium Biblicum （思高） Chinese Bible, with 7000 pages. I found that most of the PDF reader fail to read any page immediately. Only Dropbox built-in PDF viewer can do it.

At the end, I tried to use F-Droid, and found Librera Reader.

It is ads-free, and can read large PDF at any page instantly. Great!!

Calibre is a great tool to create ebooks such as EPUB format. I sometimes convert ODT format to EPUB format so that I can read some documents on my Android phone, using FBReader.

Recently I downloaded some PDF ebooks. And when trying to read from laptop, it causes eyestrain. Unlike journal articles, a journal article usually uses the layout of two columns. More columns mean that the text has narrower “width”, and it helps reader to track the line easily.

HTTrack Website Copier is always my favourite. Internet is not always available. Download a website, especially articles, for offline reading is always a good solution. HTTrack is the best. Previously I used GUI, but in Linux, command-line is a better method.

On the other hand, Android e-book reader I used most is FBReader. It supports multiple e-book format, especially EPUB. FBReader is easy to use, and there is night reading mode. Furthermore, it is open source and available in multiple platforms.