Good App to Learn Vocabulary

Dictionary.com's Flashcards is a good and free app from Dictionary.com. It is actually an app to help you to organize your vocabulary flashcard desk. This app allows you to create your own vocabulary lists and share your lists to others. Moreover your lists can be synced.

Now you no longer need to create your own flashcard desk and bring it along with you. You can study vocabulary on your way with you phone.

Updated: I found that there are some popular words which I could not find it from this app. To add these missing words to your list,  you can add from Dictionary.com website, then choose the tab "Word Dynamo". Now for each word, you can use the definition suggested by Dictionary.com or you can use your own definition. I like this feature. The definition from Dictionary.com is lack of  sample sentences, I prefer use definition from Oxford or Cambridge dictionary with sample.