If you're not familiar with Quizlet, it's an amazing resource for making online flashcards, but it will use your terms to create tests, spelling games, and other interactive practice tools. You can either upload your list of terms or search through the thousands of already created lists. Everything is free, except for a few premium features, which I have never needed. It is also customizable in any language with very high quality audio pronunciation!
Quizlet is not a new resource. It's been around since 2005 and I've been assigning them for years as a study tool before assessments, but recently I started using it as part of a flipped classroom approach and it's changed everything!
I create the quizlet for my students and have them "learn" the words for homework. I keep the lists short (under 20 terms, but ideally under 10), which is really important because we know the human brain can only learn about 7-10 new words a day. They must use one of the study tools with the audio before they can play the games or take the test. It's important to me that they hear the words pronounced correctly.