iOS App 5.7.0. terribly freezing on iOS 9.3.2

[pianomax]

..after the 5.7.0. app update (in iOS 9.3.2) the app freezes constantly. After areboot or force close, the first song is played Ok, but after 1 minute or so, scrolling or going back and forth in the app as well as playing music + unlocking the iOS lockscreen causes a  complete freeze of the app. 1 time completely crashed even iOS till reboot. Prior there were no problems, no other things habe changed on the device.