i gave up searching what's causing that resprings..i did everything to my 5s and mini 2 retina get back to normal..but it didn't work..it's definitely clear that it's a firmware issue that's keep going from 8.3 and 8.4..and it looks like we have to wait until iOS 9 comes out..
I also have a 5s and iPad mini 2 and also have resprings issues now and again (once a week maybe) and not with a specific app. Both devices run on iOS8.4 and i'm also having these issues since 8.3. I hope this will be resolved in 8.4.1
I did notice that it happens more with the iPad mini2 then the 5s for some reason.