Diary app RedNotebook uses txt2tags
Jendrik Seipp wrote me to tell about his diary application RedNotebook. As the website says:
RedNotebook is a graphical diary and journal to keep track of notes and thoughts. It includes a calendar navigation, customizable templates for each day, export functionality and word clouds. You can also format, tag and search your entries.
If you click at the image above, I guess you'll recognize those === and ** from somewhere... :)
What about writing your notes using our beloved markup in that beautiful application? Give it a try!