Vitadi is a free-to-download dictionary app for iPhone that allows you to learn English in a fast and efficient way. The dictionary has an offline mode, which allows you to look up words without an Internet connection. The app can be used in multiple languages, including English, Vietnamese, and many other languages.

Vitadi is also an English-Vietnamese dictionary, which helps you learn and practice vocabulary, pronunciation, and translates English to Vietnamese. You can also use the app to learn English, and practice pronunciation and vocabulary, according to the study programs, topics, and levels.

Vitadi can be used to look up words in different ways. You can search for words in a variety of ways, such as by their meaning, by pronunciation, or by their spelling. You can also search for topics, which makes it easy to find the words you are looking for.