A new issue has arisen in iOS devices. This is related to the device's zoom feature and it might look something like this.
In order to fix it, you must change the option from zoomed to standard. It will start working properly after rebooting the app.
Follow these steps: Settings > Display & Brightness > Display Zoom > View > Standard
Unfortunately, if you have an iPod 5/iOS 7 this workaround will not work as that model does not have the Zoom option.
The fix is now available, just go to the App Store and you'll find an update that will solve this issue. Unfortunately, for iPod 5 and iOS 7 we are still working on it.