Spotify Alternatives
-- koel Free
Open Source
https://koel.dev/
Demo: https://demo.koel.dev/
https://github.com/koel/koel/
Netflix Alternatives
-- Stremio Free
Open Source
https://www.stremio.com/
https://github.com/Stremio/
-- Watchit Free
Open Source
https://watchitapp.site/
https://github.com/ZorrillosDev/watchit-app/
Adobe Acrobat DC Alternatives
-- PDFTK Builder Free
Open Source
http://angusj.com/pdftkb/
-- GImageReader Free
Open Source
https://github.com/manisandro/gImageReader
-- PDF Arranger Free
Open Source
https://github.com/pdfarranger/pdfarranger
Youtube Alternatives
-- SkyTube Free
Open Source
https://skytube-app.com/
https://github.com/SkyTubeTeam/SkyTube
-- SongTube Free
Open Source
https://songtube.github.io/
https://github.com/SongTube/SongTube-App
Others
-- TOS;DR Free
Open Source
“Terms of Service; Didn't Read” (short: ToS;DR) is a young project started in June 2012 to help fix the “biggest lie on the web”: almost no one really reads the terms of service we agree to all the time.
What does “ToS;DR” mean? the name is inspired by internet acronym TL;DR which stands for "Too Long; Didn't Read" and is often used on blogs and emails when a block of text is just really long and that people are too lazy to read the whole stuff. It was intended more as a code name than as a real name. But it seems that people like it (do you?)
https://tosdr.org/
https://github.com/tosdr
-- AlternativeTo Free
Proprietary
https://alternativeto.net/
-- Free Software Directory Free
Open Source
https://directory.fsf.org/
source code: https://agpl.fsf.org/directory.fsf.org/