The effect of the moving background is quite cool, there's no doubt about that, but hey, if it's going to cause us some discomfort while using our iPhones and iPads, we'd gladly do away with it. And thankfully, there is a way to disable the iOS 7 parallax effect! You just have to follow these simple steps:
1. Open the Settings app;
2. Go to General;
3. Go to Accessibility;
4. Activate 'Reduce Motion'.
Once you've done all that hard work, the background will no longer move around as you tilt the device. Enjoy using the new iOS 7!