Placing a screen protector on a cracked phone screen can be a temporary solution, especially in scenarios that involve minor, hairline cracks. A screen protector can also help with more significantly damaged glass, as it may help prevent injury from glass fragments. However, a screen protector shouldn't be a permanent fix for a broken display, as it won't miraculously increase the durability of the cracked screen. While the screen protector might give users a false sense of security, the display integrity is already compromised. Additional drops and even the pressure involved in applying certain screen protectors may produce new screen damage.