From Jendrik Seipp:
RedNotebook is a modern journal. It includes a calendar navigation, customizable templates, export functionality and word clouds. You can also format, tag and search your entries. It features tagging, spell check, format your text bold, italic or underlined, insert Images, files and links to websites, links and mail addresses are recognized automatically, live-Search, automatic saving, backup to zip archive, and export the journal to PDF, HTML, Latex, or plain text.
What's new in this version:
Version 1.7.1 includes spell checking correction in the correct position.
It's free, along with a wiki on the website to help if there are any problems. It's perfect for keeping a diary, and comes with a search function and a word cloud. It also has a spell check. It's simple. The files are portable, and there is an export and backup option on the program.