If you are a Windows Phone user you must know that filling in forms in apps is usually a real pain. There is no good way to move from one input to another or to collapse the keyboard. The whole process becomes a struggle, tapping outside the input fields to collapse the keyboard allowing you to scroll to the next input or to the submit button at the top of the screen, usually occluded by the keyboard.
The typical struggle to get to the last input fields and the submit button may look like this
There is no guidance on how to approach this. Take a look at the Store app on Windows 10 mobile, the perfect example of bad UI and UX directly from Microsoft and try review an app. You fill in the title of the review, then struggle to go into the review text input, you have to tap somewhere above the input to hide the keyboard, but not to hit the stars control … just an UX disaster.