Nextcloud is an open source, self-hosted file share and communication platform. Access and sync your files, contacts, calendars and communicate and collaborate across your devices.
Firefox Send lets you share files with end-to-end encryption and a link that automatically expires. So you can keep what you share private and make sure your stuff doesn’t stay online forever.
Locally hosted web application that allows you to perform various operations on PDF files, such as splitting, merging, adding images and many more!
Calibre-Web is a web app providing a clean interface for browsing, reading and downloading eBooks using an existing Calibre database.
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.