How to download deb files from cydia to computer
This will show you how to download any deb file from cydia and extract it to you computer
Very useful for the essential deb file like appsync etc
Connect your iphone to your computer via the usb

You need a file browser I am going to use iFunbox but you can use any its your choice
Open your file browser and navigate to var/cache/apt/archives
As you can see from the image below there is nothing in there at the moment

Open cydia and search for a deb file you want to download as an example I have searched for open SSH and as you can tell by the green tick its already installed

Press confirm and download the package to you iphone

Once its download and installed your iphone will delete the deb
(You just need to do the following and you can keep it)
All you need to do is once its finished downloading, Hit the refresh button in iFunbox

Now you will see the downloaded deb file

Last thing to do is coy the deb to your computer

You can also do the same procedure but without the computer and iFunbox by using iFIle just move the deb to a different directory and transfer it to you computer later credit to sinfuliphone