Unlike iOS’s Notes, OS X’s built-in app for quick notes, Stickies, goes beyond simple text. Still, it feels dated these days, and perhaps its biggest flaw is that it doesn’t sync across Macs or with your iOS devices. If you’re looking for something a bit more modern that lets you create and manage text notes, and access those notes anywhere you’ve got an Internet connection, Justnotes (Mac App Store link) may be the solution.

Justnotes’s main window uses the now-familiar two-paned interface: a list of your notes on the left, with the content of the selected note on the right. (You can choose to show a preview in the list for each note’s contents—one, two, three, or four lines.) The first line of each note is displayed in bold as the note title, and next to each note’s title is the date the note was last modified; for items modified today, you see the time of the last change. A search field lets you quickly find all notes containing your search string; instances of that string are highlighted within each note. You can sort the notes list alphabetically or by creation or modification date.

Select a note and you can immediately edit it in the right-hand pane; double-click a note to open it in a separate window for editing. To create a new note, you simply click the pen-on-paper button, press Command+N, or choose File: New Note. Justnotes also offers a handy, systemwide keyboard shortcut that brings Justnotes forward and creates a new note, making it easy to enter some quick text regardless of which app you’re currently using.

Justnotes stores notes as plain text, which means that note formatting is limited—font and size, alignment, and a few other basic tweaks—and those choices apply to all notes.

What makes Justnotes so useful is that it syncs your notes across devices, and it offers two sync options. The first is to sync your notes database using Simplenote, a free text-note-syncing service. (A premium Simplenote account, which costs $2 per month or $20 for a year, offers a number of features beyond simple syncing.) In addition to keeping your notes in sync between multiple Macs, Simplenote also provides Web access to all your notes, and it makes your notes accessible using the Simplenote iOS app and a number of third-party apps that support Simplenote syncing.

Alternatively, if you’re running OS X 10.7.3 or later, you can choose to store your notes as plain-text files in a folder on your hard drive. If you use Dropbox, and you choose a folder inside your Dropbox folder, this means your Justnotes notes are automatically synced across all your Dropbox-enabled devices, and they’re also accessible from any Dropbox-enabled text editor or notes app—for example, an iOS text editor. With folder syncing enabled, Justnotes automatically includes in your notes list any .txt files in your synced folder, although you can configure other plain-text file extensions (such as .md and .markdown) that you also want the program to recognize.

My favorite sync feature, however, is that you can sync with both Simplenote and a local folder, and you can even configure multiple Simplenote accounts and multiple local folders, letting you store, say, work notes in one Simplenote account, shared family notes in another, and personal notes in Dropbox. Each account or folder gets its own heading in the notes list, with that account or folder’s notes listed below it.

A given note can sync to only one location, and new notes appear in the first account or folder you configure—the one at the top of the list. (In Justnotes’s preferences, you can change the order of accounts and folders in the list.) However you choose to sync, Justnotes syncs automatically, or you can force a sync by clicking the Last Sync text at the bottom of the window—notes that haven’t yet been synced display a small, gray circle to the left. Because notes are plain text, formatting is handled locally, so only note content is synced.

You can transfer notes between Simplenote accounts and synced local folders by simply dragging a note from one section of the list to another. I experienced an occasional glitch with this feature, especially when dragging a note from a Simplenote account to a synced folder—sometimes Justnotes wouldn’t move the note—but it generally worked fine. One feature I’d like to see is the capability to collapse an account or folder’s section of the notes list to hide that section’s notes.

Justnotes provides a number of actions for managing notes. You can send any note, regardless of how it’s synced, as the body of an email message or export it as a PDF file. For notes synced using Simplenote, you get additional options: You can mark a note as a favorite (which moves it to the top of the list), and you can add tags to notes; these designations are synced only across Simplenote. Tags are useful mainly in that searching for #tagname lets you quickly view all notes with that tag.

If you no longer need a note, you can right-click (Control-click) the note in the list and choose Archive (or select the note and choose Note: Archive—oddly, there’s no archive/delete button in the window). Rather than deleting the note, this action saves it to Justnotes’s archive. You can view the archive by clicking the Archive button at the top of the window. This view mimics the main notes view—list on the left, selected note on the right—but lists only notes you’ve archived. You can restore an archived note to your main notes list at any time. Alternatively, in archive view the Archive command is replaced by Delete, which permanently deletes the selected note.

If you’ve already got notes stored elsewhere, Justnotes can import plain-text files and Evernote notes. It can also export your notes as plain-text files, although the app crashed every time I tried to use the export option.

I do have a few quibbles with the ap. For one, I’m not a fan of the way Justnotes names new notes created in (or moved to) a synced folder: Rather than use the first line, or first few words, of the note as the file name, Justnotes gives these files names like D91A41ACDAB9A5B76499C9EAE7432189.txt. For those of us who want to open our notes in a Dropbox-enabled iOS app, this naming convention makes it impossible to figure out which note is which. I’d also like to see a Duplicate command for making a copy of a note, and I’d like to be able to delete a note immediately, rather than go through the intermediate Archive step. And though Justnotes does offer full-screen mode, the width of the window is set—on my 27-inch iMac, I couldn’t make the window wider than roughly one third of the width of the screen. Finally, a pie-in-the-sky wish is for Markdown support for basic note formatting.

Nevertheless, Justnotes’s interface is simple but effective, mirroring the elegant look of the Simplenote iOS app and website—if you’re already using Simplenote, Justnotes is a no-brainer purchase. But it’s also a very nice OS X notes app, and its sync options will make it especially appealing to those with iOS devices and multiple Macs.

(Justnotes is currently $6, but the price will increase to $10 after an unspecified introductory period. Justnotes works with any version of Lion, but the developer notes that syncing to a local folder requires OS X 10.7.3.)

[Dan Frakes (@danfrakes) is a senior editor at Macworld.]

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