https://play.google.com/store/apps/details?id=sinhhuynh.english.englishfarm
This free farming app-game is especially helpful for GRE/GMAT test takers.
More than essential 3500 words with definition, example, pronunciation audio.
* Track learning progress
* Add your own note for each word
* Audio works offline
* Word Blacklist, list the word you hate
USAGE: YOU HAVE A ENGLISH WORD FARM, WATER YOUR PLANTS EVERYDAY(REVIEW WORDS)
SO THEY MAKE FRUITS