Are you wondering how to install DEB files on iPhone manually? Well, You can easily install DEB files on your iOS device. If you want to install jailbreak tweaks without opening Cydia then you will need to have an FTP client and the .deb file of the package you want to install. You can use FTP client like iPhone Explorer or Cyberduck. After downloading the .deb file of the package simply follow the steps posted below using which you can easily install the .deb file on your iOS device.
How to Install DEB Files Manually
STEP 1. If you are using Cyberduck, simply launch SFTP client and then login.
STEP 2. Now you have to go to /var/root/Media on your iOS device, then simply create a Cydia folder there.
STEP 3. Then open the Cydia folder and create another new folder entitled AutoInstall.
STEP 4. Now you have to place the .deb file in the AutoInstall folder.
STEP 5. Then simply restart your iOS device twice.
You will be able to see the new package in the springboard of your iPhone and in Cydia after the 2nd restart. That’s it. In this way you can install .deb file on your iOS device. [Via]