Busuu is described as 'Offers courses for 12 languages, with expert-created lessons in grammar, vocabulary, reading, writing, listening, and speaking, plus community practice and placement tests' and is a language learning tool in the education & reference category. There are more than 100 alternatives to Busuu for a variety of platforms, including iPhone, Web-based, Android, iPad and Android Tablet apps. The best Busuu alternative is Duolingo, which is free. Other great apps like Busuu are Memrise, Rosetta Stone, Mondly and Babbel.
both has own quality. For examples for building vocabulary best to use vocabulary.com besides for grammar and spoken English best use busuu