Johnny Grammar Word Challenge is an educational application developed by the British Council for iPhone users. The game is designed to help English learners test their knowledge of common vocabulary, spelling, and grammar that appear in day-to-day English. The game's objective is to answer as many questions as possible in 60 seconds.

The game is divided into three difficulty levels - Easy, Medium, and Hard, and three categories - Words, Grammar, and Spelling. There are ten topics that include Food & Restaurants, Travel, Idioms, and Hobbies. As you progress through the game, you can earn badges and share your score with others on the leaderboard. The game also allows you to compete with others on a global leaderboard. Feedback is given for the wrong answers so that you can learn from your mistakes.

Overall, Johnny Grammar Word Challenge is a fantastic app for English learners who want to improve their vocabulary, spelling, and grammar skills. The app is easy to use and has a user-friendly interface. It is an excellent tool for anyone who wants to learn English and have fun at the same time.