Day One - A simple journal application for the Mac, iPhone, and iPad. AboutTo learn more about Day One, see these two excellent reviews . PublishPublish is not available in Day One 2.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.
Reminisce Journal - Reminisce Journal is a free iOS and Android app that helps you to capture live moments, daily activities, thoughts, ideas and travel logs, etc.
Standard Notes - A safe place for your notes, thoughts, and life's work
Grid Diary - The simplest way to get started with keeping a diary