Learning vocabulary is always a challenge to language learners. I´d like to share two sites which can be extremely helpful to students when studying. Both sites let you create word flashcards for free.
The 1st one is Cramberry. It´s very simple. You sign up for free and then can create sets of word cards (front + back).
The second one, is my favourite. I´ve been using it with my EFL intermediate students. I´ve created sets with the vocab they are supposed to know for their English exams and make it available to them. I also use the different exercises in the set in class on the interactive whiteboard as a warmer.
This is how it works: you create a set with words + definitions or questions + answers. Then the website generates 5 memorization exercises for the vocabulary set. If your students sign up, you can even see who has done the exercises and their score. This is a set I created about vocabulary to describe people.