Excellent appli for a very little price. I can both practice my English and my Chinese at the same time, the story-based explanations are very useful and smart. I can know express my ideas and my opinions about some topics only by using 4-characters idioms and not struggling in finding the correct words ! But as the first idiom says, this appli would be not enough if theres only 按圖索驥 ! This is a must buy for the people who want to start mastering Chinese !