While it is possible to apply SureShield or Ultra Liquid Glass to a cracked screen, we would strongly advise against it as 1) the level of protection offered by the coating will be dramatically reduced and 2) if you are using SureShield, you will not be able to register your device for the Device Reimbursement Guarantee with a cracked or broken screen. We would always recommend that you replace a cracked or broken screen before applying any of our liquid glass products.