There are plenty of flashcard services on the web that students can use for rote practice of vocabulary words. The following five apps offer a little bit more than flashcards by providing some larger context for the words and phrases that students can study through them.
English Monstruo is a free app (iPad and Android versions available) containing eight games designed to help students learn verb conjugation. English Monstruo was developed by researchers at Cambridge University who examined the results of 200,000 exams to determine the words that give Spanish speakers the most difficulty when taking an English exam. The games in the English Monstruo app contain activities ranging from fill-in-the-blank to sorting words to replacing incorrect words with correct words. Each game has a series of levels to work through to earn points and unlock increasingly more difficult levels. To access all eight games a player needs to first earn the maximum points in the first six games in the app. This app is no longer available – August 2019
Phrasalstein, developed at Cambridge University, is a great iPad app and Android app designed to help students learn the meanings of phrasal verbs. The app has a practice mode and a quiz mode. In the practice mode students select a verb and a preposition combination then see a short animation demonstration of the meaning of the chosen phrase. In the quiz mode students see an animation then have to select the matching phrase. Translations of the meanings are available in Spanish, German, Italian, Russian and French. Update: as of August 2019 this app is only available in Android.
Duolingo is a free service that aims to help you learn Spanish, French, German, or Portuguese. Duolingo offers mobile apps that allow you to practice a new language anywhere you go. The Duolingo mobile apps and website provide a variety of translation activities to help learn to you read, listen to, and translate words and phrases. The activities include looking at pictures that are representative of words and phrases. After reviewing a couple of pictures students are asked to type translations. The app gives immediate feedback to students.