Some bug happened on my cell phone

Dont know why after I updated my system to iOS 8.1.1 the vocabulary app always froze on the last review page and wont go back to the main page. I have to turn the app off and open again every time I finished review vocabulary. Please help and fix it! Thank you very much! I love this app!

angel0911 about 沪江开心词场-多语种趣味闯关背单词