This app was mentioned in 3 comments, with an average of 1.67 upvotes
An actual awesome Haiku App for iOS & Android: iOS: https://itunes.apple.com/gb/app/haikujam-create-poetry-together/id727512858?mt=8 Android: https://play.google.com/store/apps/details?id=com.herokuapp.haikujam&hl=en_GB
There is app but for Haiku (Japanese poem format which has only three sentences). https://play.google.com/store/apps/details?id=com.herokuapp.haikujam