You can remove your application at any time by either selecting it in the sidenav after it has been created and scrolling down to the bottom of the page, or by selecting the action in the dropdown next to it on your Dashboard. When you choose to remove your app, the entire directory will be removed.
{warning} Since your workspace directory is mounted as a volume in your container, removing the app will remove it completely from your machine. Be sure to commit any changes that you don't want to lose before your application is removed.
As one final note, removing your application will not remove the alias that was added in your hosts file. While there's no danger to leaving it there, you're safe to remove it without having any impact on your workspace.