English Word Formation is a free offline dictionary developed by NSGS that is designed to aid language learners and teachers in their studies. It is particularly helpful for those preparing for FCE, CPE, and CAE exams.

The app offers a wide range of features, including translations of main words and deriving words that have a different meaning from the root word. It also provides audio pronunciation with British and American voice versions, alphabetical listings, and a favorite list for those who want to save words. Another useful feature is the keyboard search function that allows users to search for words while typing.

In addition, the dictionary includes abbreviations for parts of speech, such as pronouns, adjectives, determiners, prepositions, and adverbs. The app also has the option to share words with derivatives, and it does not require an internet connection for use. The app is regularly updated and has flexible font size settings for user comfort. It even has a different layout for tablet users, making it a versatile and user-friendly tool for language learners and teachers alike.