Wordzzz lets you translate words and subtitles in Safari. Wordzzz extension analyzes subtitles in your YouTube and Netflix player (subtitles must be enabled) and when you hover over a word, the video stops and you can click on a word to see the translation card. All translated words can be added to your vocabulary.
One World Dictionary by Ascendo is a leading multilingual reference tool for Apple desktops.
InstantTranslate makes it really easy to translate a selection of text in the application you are working in from one language to another language.
