Free online English to Chinese dictionary (Traditional and simplified). This website is very simple and easy to use. It also offers various tools such as flashcards, quizzes, text annotation, Chinese text input and more.
Click here for the link
Pleco is a very useful mobile Chinese English dictionary. The feature I found most useful was the full screen handwritting input which is free! Other free content includes an integrated Chinese English dictionary with a flashcard system. Other more advanced features such as the document reader and live camera-based character lookups are fee based.
Quizlet enables you to create your own flashcards or search an archive of flashcard decks from other students.You can easily find flashcards for learning mandarin words on Quizlet.
Quizlet for Android
Quizlet for iPhone
Practice Your Handwriting
Chinese Zibaobao helps your kids to learn to read and write Chinese characters and words in a fun and intuitive way any time, anywhere. As an alternative to writing on paper, try this tool allows you to practice your Chinese handwriting on your personal mobile devices.
This app is only available on the App Store for iOS devices.
Decipher Chinese - the news app for Chinese learner
If you are like me, someone who spends a lot of time commuting, this is a great app for you to learn to read Mandarin on the go, with bite-size news and magazines articles made easy for students. You will be able to access free daily articles written by experienced teachers specifically for learners.
Lingua Pinguin - Interactive English-Chinese Picture Dictionary
LinguPinguin is an interactive English Chinese picture dictionary with audio function. It is catergorised in themes including nature, transportation, animals etc. You can even challenge yourself in the quiz section.