This is wonderful reference that can be used to look up words you would like to know.
Duolingo is an application/website set up in a game format that teaches words, practices listening, and speaking. While the information on Duolingo is not tied directly into the curriculum it a great way to support and increase their use of Spanish.
This is an application/website that students can use to practice specific vocabulary or skills. Students are able to use some teacher created quizzes/flashcards and to create their own.