Mate Translate - Ultimate translation app for Mac, iOS, Chrome and many more
MacLinguist - A pop-up translator for Mac and Windows that works with any application
Google Translate - Google's free service instantly translates words, phrases, and web pages between English and over 100 other languages.
Bubble Translate - A mac menu bar app for translating
Linguee - English Dictionary and Translation Search with 1,000,000,000 example sentences from human translators. Languages: English, German, French, Spanish, and Portuguese
Stepes - On-demand chat based translation app