I was looking for a journal application which I could use every day, and also one which allows me to choose fonts, do full searches across all journal entries, and uses encryption to protect my entries from prying eyes. After trying several other journaling applications, I found MiJournal. Its interface is very simple and clean, it allows full editing using all the Mac fonts and formatting functions (why do some journal apps not make it simple to underline or use boldface?) MiJournal allows it all - including strikethrough, kerning, superscripts, subscripts, etc.
Some journal apps use password protection to open their program, but the text files they generate are in clear text for anyone to read, without any encryption. MiJournal uses both a password as well as encryption.
Searches in MiJournal can be within a days journal entry, or across all journal entries, and is very fast, returning a list of not only each date, but a sample text where the searched word has been found.
I believe the author is very responsive to feedback, when I contacted him, I had a reply almost immediately.
MiJournal does exactly what it should do: Simple, basic journal entry. But it also goes far beyond, allowing you to edit using the normal Mac tools. This is the journaling app that I am now using.