Thank you for participating in this project!

To contribute, please read the following guidelines.

Rules:

If you would like to improve this project by adding/suggesting edits to the contents, pulls requests are always welcomed. Please:

I am trying to make each list/section as self-contained as I can. So, please feel free to add duplicate links to different lists if necessary.
Only try to submit free and quality resources related to the topics included in the table of contents. Only submit paid resources if they are high quality and you highly recommend with a paid tag at the end. Add paid sites at the end of the list you are trying to add it to.
Follow this convention: [resource](link) - a short description if necessary and try to put highly recommended resources first.
Check spelling and grammar.

Free means entirely free, not freemium, free trial or limited functionality resources. If some resource is freemium or offers a free trial only, mention it with a freemium tag at the end.
Your contribution may be denied if the resource does not satisfy necessary curation.

Now let's make this list awesome and even more valuable!