This paper reviews WordUp, a mobile application which fosters English vocabulary learning through exposure to new words in authentic and engaging contexts such as excerpts of movies, songs, and news programme. The samples of use are introduced after the definition of the target words have been provided in both the learners' first language and English. In this review, the advantage of extensive exposure to authentic use of the target words will be discussed. Moreover, some of the app's shortcomings such as its unsuitability for beginner learners and insufficient tasks to improve the users' production of the learned vocabulary will be highlighted. WordUp is recommended for learners above level A1 The Common European Framework of Reference for Languages (CEFR) who wish to learn the appropriate application of the learned material through authentic input.