Screen goes black after starting application under iOS9
After upgrading from iOS8 to iOS9 on my iPhone4s I experienced poor performance when starting some applications. E.g. if I start Contacts app, then instead of showing the contact book screen goes black and this situation seems to have no end. It can be stopped by pressing start button. Then the application goes to background. After picking it up from background using application scroll (double click of start button), address book is displayed properly. Similar behavior can be experienced with other applications. Some of them, being picked up from background freeze for very long time. Sometimes they unfreeze after a while by themselves and sometimes they have to be killed and started again. iPhone reboot also helps but this is the way to be used frequently for solving problems.
Does anybody experience the same problem? Is it solvable or I need to wait for new iOS9 patch? Do apple know that this is an issue. Upgrade from 9.0.0 to 9.0.1 did not solve it and e.g. Contact app is a built in one.
iPhone 4S, iOS 9.0.1