This is a Japanese - English, English - Japanese dictionary.
The app supports Japanese-Japanese, Japanese-English, English-Japanese, English - English, Synonym and Antonym dictionaries.
You can translate text by selecting “Translate”, typing the text you want translated and press “search”.

You can add words that you look up often the word list. Open the list by tapping the book icon.
Click the “+” button to add words. Delete words by pressing delete and then tap on the word you want to delete.