Interface

Built with a focus on absolute simplicity, this application is a joy to use for my task lists. It allows a hierarchical structure of categories or projects - each with their own task items. Sub-projects can be collapsed to simplify the interface even more.

Each item is added to the appropriate list with just a title and a date. A variety of date formats are recognized automatically upon submission - "Next Wednesday" is just as acceptable as "20 Jun 2007", and "+5" translates to due in 5 days. Some abbreviations are also accepted: if I want a task due fortnightly on Mondays, I type "ev 2 mon". In similar fashion, priorities can be assigned directly in the title of the item by using syntax shortcuts such as "!p1" and "!p2".

Quickly add an item

Everything about this application begs for power-users. You can just use it as is, using the mouse for most options and typing as necessary to fill in the details. Just like the date and priority shortcuts, however, everything else can be done faster and faster as you get a handle on the powerful keyboard shortcuts.

The interface itself is very straightforward. Virtually all functionality is Ajaxified for speed and the display of help files and information is done via lightbox popups. There are virtually no other page loads once you've logged in. However, informative pages are available at real URLs for external reference. The downside to all that speed is that the application was not built with accessibility in mind - no JavaScript means no Todoist.

Choose 'Reorder' to move your items around by click and drag

API

Like all the best web applications, Todoist offers a comprehensive API that offers access to all of the basic functionality. This allows what is quickly becoming the most highly sought prize of Web 2.0 - ubiquity of access. The simplicity of the API means that a developer network is rapidly building up around the tool. Mac OSX users can access it via Quicksilver or the Dashboard widget. Todoist creator, Amir Salihefendic, has also released a widget for Netvibes and iGoogle that completely replicates the app's functionality from within your own page on those sites. There is also a Firefox extension for Gmail that allows you to delegate emails to your task lists for dealing with later. And another that allows access to Todoist from your browser status bar. Naturally, Todoist has a mobile site for quickly checking or adding items when out and about. All in all, a multiplicity of touchpoints increasingly reminiscent of Twitter.

I've made a big deal about the simplicity of this interface, but for good reason. Todoist is easier to use than Ta-da List and it's much lighter than Remember the Milk. If you're looking for the simplest, easiest way to keep track of your tasks, this might just be it.

Negatives

There are downsides, of course. As mentioned above, accessibility appears not to have been considered. Another major feature some people might miss is notifications. Todoist doesn't remind you of tasks, nor does it let you know when you've missed them. You have to be using the app to keep track. It mitigates that to a certain extent by being available in more locations, but it certainly pales in comparison to Remember the Milk's comprehensive methods of notification.

Conclusion

Todoist is an elegant, effective and efficient application that lets you sort, arrange and prioritize tasks easily. The lack of notifications is the only major feature missing. Given it is the work of one developer, it's rapid pace of development is astonishing and I doubt notifications will be unavailable for long. I expect it to improve still further in the immediate future, particularly as more developers take advantage of the API to tie it into other applications.