Lifeograph is a free open source digital Journal, Diary and note taking application for linux, Windows and Android. It is a private diary application comes with real AES256 encryption support. It also comes with automatic titles and subheadings formating and automatic time out feature. It supports rich text formatting, searching, filtering and Spell checking. You can insert images and charts in your diary entires. Some other features are themes, automatic backup, export file to plain text and print option.