Projects archived can be restored very easily within the app.
How to unarchive/restore a project?
Step 1: Select Archived from the Status drop-down at the top.
Step 2: Select the 3 vertical dots to the right of the line item for the project you wish to restore, and select Make Active.
Step 3: Select Active from the Status drop-down at the top. Your project will now appear in the Active list of projects.