I can definitely say it's one of my favorite learning platforms. You can deep into a huge amount of different exciting stuff for learning a language. You can choose your own way to learn a language and at first, you can find and choose a language you are struggling about from a big list of available languages to learn.
Word of the Day - Learn one new word, every day
Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.
Memrise - Learn a new language with games, humorous chatbots and over 30,000 native speaker videos.
Wordd - Quickly look up vocabulary, abbreviations, acronyms, slang
Polidict - Elevate your vocabulary with the advanced learning web service
Synonymful - Improve your vocabulary and communicate like a pro.