Does using pangu to jailbreak an iOS device delete your currently-installed apps?
Installing the jailbreak will not delete your apps, but it is generally recommended to backup your phone, do an "Erase All Content", and install the jailbreak with only the OS on the phone. You can then sync your phone to get all of your apps back after the jailbreak is installed. You should probably allow around 2 GB for the jailbreak, possibly more if you plan on installing a lot of packages.