Here there are lots of podcasts for learning/teaching communicativa functions. Some resources you'll have to pay, but there are also many which are free. The best thing is how they are organized: introduction, dialogue, exploded dialogue. I always use them with my adult learners, they love them.
Free online resources for teachers and students. There are articles, short stories, crosswords, grammar explanations, and much more. For all levels and ages.
You won't find all terms in any dictionary. Urban dictionary stores the latest coined terms. Adolescents love listening to music and checking new words.
Make a puzzle for your students for free. This is just a tool, perhaps not a resource, but which cild doesn't love making puzzles. You can use it also with adults!