Open the App Store and sign in
Update the app manually
In the App Store, try to update the app manually.
Check your payment method
You may need to have a payment method on file, even if the app you want to download is free. See what payment method you have on file and make sure it hasn't expired, been declined or has failed.
If you can't update apps and you see a message that says “your account is disabled in the App Store”, there may be a problem with your payment method. Contact Apple Support for assistance.
Pause the download, then restart it
When you touch and hold the app from the Home screen, you may see options to Resume Download, Pause Download or Cancel Download. If the app download is paused, tap Resume Download. If it's stuck, tap Pause Download, then touch and hold the app again and tap Resume Download.
Restart your device
If you still can't download or update apps on your iPhone or iPad, contact Apple Support.