The app is quite useful for translating and looking up words, but it does have one issue; the output information is always in black font which blends in with the background, it seems, on the dark iPhone appearance. If it changed with the brightness or made the font not blend in with the background, it would be an easy 5 star. Unfortunately, that is not the case. To use it, you need to change your phone appearance to light every time you want to use it, which is quite inconvenient.
For translating though, it works well. 5 stars for that. - 1 star for poor design.