Frictionless is based around two basic concepts, actions and contexts.

An action is something you can do. It's something you need to do. The problem with any list form of to-do list though is that life isn't that simple. What you really need is a to-do outline when you're organizing. That way you can break down large problems into their components, components that can be easily accomplished. That outline has to be dynamic, so that when you come to an action that turns out to consist of many other actions, you can immediately turn that action into a collection of actions.

In Frictionless, any action with sub-actions is termed a project.

However, outlines suck as way to do things. When you're doing, you don't want to have to navigate through an outline, you want a list of things to do, and more specifically, you only want a list of things you can do right now. If you're running errands, you want a list of errands you can do, not a list of things you can only do on your computer. Which is where contexts come in. A context is something like @work, @home. Contexts are the standard GTD way of taking a 200-item master to-do list and winnowing it down to the 10 things you could realistically be doing at the moment.

So you need one view for organizing, and you need a completely different view for doing. The doing view needs to be filtered by what you can do at the moment.

Which brings us to the Action Browser, which is the core of the Frictionless user interface.

The Action Browser can have up to 3 panes visible at a time. The first pane is the filter pane. It determines what is visible in the other two panes. For instance, if you chose "Work" under Contexts in the Filter pane, you will only see actions in the other two panes that relate to the Work context. If you choose "Last Week" under Time in the Filter pane, you will only see actions in the other two panes that happened in the last week.

The second pane is an outline pane. Here you can organize your projects and their associated actions. This is most useful for organizing and planning.

The third pane is the action pane. Here you only see actions. This view is most useful for doing.

The key part of the user interface though is that you can turn off the parts you aren't using. You can do that via the button in the upper right corner. Eventually, you'll be able to save away configurations of the action browser that are specific to certain types of GTD activities such as your Weekly Review.

So to get started, you can simply add items to Frictionless using either the Add Sibling Action or Add Child Action menus or the equivalent buttons at the bottom. You can drag items around to rearrange them as needed.