Data for projects and files are saved to an external storage and they are subject to that service behavior. It is important to download the projects when backups are required.
All actions related to project management can be found at the top menu bar, by clicking the down arrow next to the project name, located at the center of the screen.
In addition to the project settings, the File menu (accessible from the button located at the top left corner) provides a way to Export and Download the project.
Export and Download
Exporting a project provides a way to take a snapshot of the current project state as a compressed zip file. All the directories and files are retrieved, including app, build, and contracts directories.