doing a device restart or soft reset. This should resolve any small phone system issues that may have caused the Amazon shopping app to malfunction. It also frees up memory on the phone, allowing it to run quicker and more efficiently. You will not lose anything if you perform a soft reset because it does not remove any of your data. Here's how you do it:

1. For a few seconds, hold down the Side/Power button until the Slide to Power Off prompt displays.
2. To totally turn off your iPhone, drag the slider.
3. Press and hold the Side/Power button for another 30 seconds until you see the Apple logo.