MeTube is a self-hosted web GUI for youtube-dl (using the yt-dlp fork) with playlist support. It allows you to download videos from YouTube and dozens of other sites.
Paperless-ngx is a document management system that transforms your physical documents into a searchable online archive so you can keep, well, less paper.
Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.