If you want to add the additional or new iPhone themes to your iPhone theme folder, then you need to add manually IF it’s not available via the installer. And to add new theme manually first off you need to have OpenSSH installed on your iPhone and use installer.app. Then next phase is installing WinSCP on the computer of yours. Go to your iPhone settings onto Wi-fi, this way to get you connected to WinSCP, then there’s little arrow that you need to click on beside Wi-fi you are connected to and take the written ip address there.
Afterward you need to open the WinSCP, to fill the forms, fill the host name with your ip address, for user name you can fill it with root and alpine for the password. And you can skip about the private key file, just leave it blank & hit login!

Once you’re logged in inside WinSCP, you can directly navigate to var/root/library/SummerBoard/Themes folder, click it, the folder contains all the iPhone theme you currently have and in this folder, you are able to add the new themes.
Now it’s time to create a folder, then create one inside your computer, name it after the title of the theme you want to add for example Computer, inside it, create another folder, name it Icons (“I” capital without quote).
Put all of the icon images you want to have inside the icons folder. Remember the icon images name must be the same names as the app title, starting with a capital (example: Photos, Computer, Table…etc). Not just that, in Computer name (main folder) you can add Wallpaper and Dock, and they must be starting with a capital.
After the Computer folder that contains a folder Icons is ready, drage them all into themes on WinScp and hit copy. When the copying process finished, you will find your new added themes in SummerBoard (var/root/library/SummerBoard/Themes folder) and you can select one of them. Remember your iPhone must be on for the file to transfer.
If you are downloading iPhone themes and iPod touch themes that is in a zip file. You will have to open the zip file and then create a folder on your computer that is the same name as the theme you are trying to download. Then copy the Icons folder from the zip file into the folder you created on your computer. This unzips the file so that you can add it to SummerBoard through WinSCP. You can also copy the wallpaper and dock out of the zip file into the file you created if you would like them too Source.
