Problems updating apps on ios 7
Uninstall and reinstall the app: If the above troubleshooting steps didn't resolve your issue, you can try deleting and reinstalling the app on your device.
The length of time will depend on the number of apps you sync to the device. After the update, try and download the apps on i Tunes.Even with the latest update on ios 10.3.1, this error would appear sometimes.First, give the app enough time to download and make sure it’s actually stuck before proceeding.Updating to the Latest i OS 10.3.1Apple often release new i OS update to fix bugs and glitches.
So always check for new update on your i Phone 7 devices.
Setting your time zone to update automatically can guard against messages like this.