Horizon Mobile Stuck on Syncing Screen (iOS 11)

This may occur on iOS 11 if you open Horizon Mobile and do not have an 'In Progress' inspection to sync over to the device. To resolve, please login to your Horizon account on www.discoverhorizon.com and click on the write report button in the work order:

Then go back to the Mobile App and click on the Menu followed by Full Sync.

If you do not have any inspections to sync over to the device and no pending data to sync back to the cloud, to break the sync cycle click on the Menu followed by Change User.