Check your Wi-Fi connection
Please make sure that your device is connected to a strong Wi-Fi or mobile data connection. If you’re using cellular data or Wi-Fi and have issues with an app, try to connect to another Wi-Fi network.
Pause and restart the app download
When you press and hold the app on the Home screen, you might see options to Resume, Pause, or Cancel Download. If the app download is paused, tap Resume Download. If it's stuck, tap Pause Download, then press and hold the app again and tap Resume Download.
Restart your device
If the app appears on your Home screen but is darkened or has a white grid with gray lines on it, don't delete the app. Restart your device, then go to the App Store and download the app again.
Please read App Store instructions for more information.