A free app for Android, by AppCloud.

This application is perfect if you have been studying English for a long time and want to improve your vocabulary. A group of linguists and teachers has developed this app, and it is the best dictionary and thesaurus for English. The app is designed to help you learn new words most effectively. The app has an extensive database of words and their definitions, synonyms, spelling, phonetic, and audio pronunciation. 

This app has been designed for English learners of all levels. You can search for words in the database by using different criteria. This is a dictionary and thesaurus with the most comprehensive database of English words.