I\'ve tried my app on iOS 7.1 and I found that the tab bar background disappears on a few occasions. I was able to track them down; it happens when:
Go in your Main.storyboard and select your MKMapView to highlighted it (cf. in Navigator area you can select « Map View »). Then look carefully where is the bottom "white square": move it up the bottom bar! In the size inspector, you can check where you place the « anchor » or view origin for this view (cf. top-left hand side in your project). This explains why it’s ok for iphone 5 which has a bigger height screen.