Extremely useful and easy to use. I carry around a pocket dictionary in my backpack (Larousse), but this proved to be far more useful and accurate. While it isnt a dictionary for slang or idioms, it does include a great deal of expressions whose meanings I have never been able to comprehend (until now...such as the infamous "macacos me mordam" expression). The dictionary also includes useful charts for "curiosities," which include things like animal groupings (i.e., a school of fish, a gaggle of geese, etc.), mathematics, and even animal voices (buzz, roar, quack, etc.). The dictionary itself is outstanding, and the app only adds more functionality (and at an outstanding price, especially when compared with the price to own the hard copy of these dictionaries!). Switching between Portuguese, Portuguese/English (translations into English), and English/Portuguese (translations into Portuguese) is as simple as touching the button with the flags to cycle through the languages. I found that searching for a word is much easier and quicker with the app as opposed to an actual dictionary.