This wiki for teachers at indispensibletools.pbworks.com is a good list of Information and communication technologies in education. (That's "ICT" to many people outside the USA.)
The list was crowd sourced from individual educators who were asked what tools they found indispensable.
Though not an exhaustive list, the wiki has a lot of possibilities. You can add a tool to the wiki by giving the product name (alphabetical order); How used; "Free" (if it is free, most are) and by adding your name in alphabetical order to the contributors list at the bottom of the page.
Here's a sample from the "S" section:
Samorost - text free puzzle game can be used to teach literacy; Used online; Free
ScrapBlog - interactive poster maker; Used online; Free
Scratch - programming language for everyone; Downloadable app; Free