If your iPhone 8 Plus touch screen is still unresponsive, try reinstalling the app. On your device's home screen, tap and hold the app icon until it jiggles. Tap the "X" sign in the top-right corner of the app. A pop-up message will appear, then tap "Delete." Return to the App Store, then find and re-download the app. Step 1: Download and install the iTunes app on your computer. If you already have, ensure that it is the latest version to avoid iPhone update errors. Step 2: Fire up the iTunes app, and using an authentic Apple USB cable, connect your iPhone to the PC. Step 3: Your iPhone will automatically detect on iTunes. XrLDdQe.