To get started, create a new todo list in the left sidebar by typing its name in the text box. Select a list by clicking on its name, and rename by double clicking. The active list appears in the main window pane. You can do the usual here: add items, check them off as completed, and destroy items. You can also tag items with one or more tags, by clicking the blue Add new tag button to the right. All your in-use tags appear at the top. You can filter the list items by selecting a tag, or click the leftmost button to return to the full list.
Inspired by Backbone's Todo Demo, with credit to Jérôme Gravel-Niquet.