It's just that some software needs the highest authority of the mobile phone to be installed. After Saipan cracked, it cracked the highest authority of the mobile phone, and any software can be installed. Visa-free means you don't have to crack the phone, but you can get the highest authority of the phone with signature software, okay? Follow-up: What does the highest authority of mobile phone mean? Answer: It seems that you are a novice among novices. The security of Saipan has been greatly improved in the subsequent versions, and the third-party software installed and operated in the system has stricter regulations. Special restrictions are imposed on the operation of some software related to mobile phone hardware and software/personal information security (for example, automatic startup of mobile phone startup is one of the restricted functions). If the installed software needs to realize the restricted function, it must be signed or cracked.