17 free and helpful things, that everyone can take advantage of
Dolly Parton's Imagination Library They send an age appropriate book once a month if you have a child younger than 5.
Project Gutenberg Lots of free classic books.
Library Genesis A great place to look for and download college/university textbooks for free, as well as other books.
Scihub Endless Free college books. (and peer-reviewed scientific publications that are otherwise hidden behind a paywall)
Khan Academy Free knowledge that you can use to clep out of university courses, or to simply invest your time in a worthwhile topic.
Openlearn UK’s Open University - free courses for all levels of study, samples of university materials, study skills and tie-ins to BBC documentaries. Everything under Creative Commons licence so you can use it as you see fit.
Duolingo The Green Owl of Languages. There are a few hundred that it teaches and the mobile app makes it easy to do anywhere while waiting (!warning! only good for Spanish, German, French, Dutch, Esperanto, and English. with anything else it gets very low-quality and short.).
Codecademy An awesome site to learn how to use some programming languages. Doesn't get into the really advanced stuff, but it's good for a start.
Photopea Completely free Photoshop clone that has all the basic features of Photoshop, using basically the same interface.
Gimp Another free version of Photoshop.
Unsplash Stock of free photos of just about anything, provided by the photographers themselves, to do with what you like.
Futureme You can write letters to yourself (or other people) in the future! You can also make notifications and reminders of a +doctors appointments or anything else important.
Heavens Above You can look up all the satellites flying over your house tonight, including the ISS, Hubble Space Telescope, those pesky Starlink satellites, and whatever else your heart desires, complete with star maps and precise timing. And there is an Android app, but unfortunately no iOS one last I checked. (For iOS you can use “Sputnik!” which is free and tells, when ISS and Hubble passes overhead.)
Night Sky Other astronomy app for iOS. If you hold your phone to the sky the app tells you what you're looking at (or point it at the ground for a view from the other side of the planet). Zoom in with two fingers and tons of deep space stuff is revealed.
Freecycle its literally people giving away stuff they don't need/want any more that they can't/don't care enough to sell.
Nexus Mods Has thousands of video game mods (for 1,509 PC games), made by independent content creators, available to download at no cost.
Archive The Archive aka Internet Archive is a non-profit library of millions of free books, movies, software, music, websites, and so much more... For example a lot of DOS games (classics like Prince of Persia, Oregon Trail, DOOM, Monkey island, Rayman, Turtles), directly playable through the browser.