How to Restore Your Cydia Apps if You Didn’t Back Them Up From Your iPhone or iPod Touch
If you have a jailbroken iPhone/iPod Touch and you bought some apps via Cydia that you forgot to backup before you upgraded to the latest version of iOS, then have no fear. Your Cydia purchases are intact! All you have to do after you jailbreak your iOS device again is log into Cydia, download and install the app that wasn’t backed up, and re-register it. It should remember your registration number. It did for my iPhone anyway. I just downloaded the Cydia app that I had bought before, opened it, clicked on “Register,” and on the page it brought up, my registration number was already filled in. I just had to click “Activate” and I was good to go! Pretty cool.
Even if you get another iPhone/iPad (upgrade to the latest version, for example), Cydia apparently transfers your purchase history to your new device. I haven’t tried that yet, but that’s what they said on HowardForums.com, one of the most well-known and respected cell phone forums on the net.
Just to be clear, though, unless you backed up your Cydia apps BEFORE you did the jailbreak (in which case you wouldn’t have a need to read this), then all of your inputted data in the app will be lost, as well as the settings. But that’s to be expected, right, since you’re downloading the latest version of the app directly from Cydia? But at least you didn’t have to buy it again!
If you want to backup your apps before you upgrade to the latest iOS, then you can do it with a free app called AptBackup that you can download from Cydia. But just know that it only backs up the LIST of apps that you downloaded, not the actual apps themselves or the app settings.
PLEASE NOTE that it does say in the instructions (see below) that you first have to “restore your iPhone and restore your backup in iTunes“, which I do NOT recommend doing. When I restored my iPhone from a backup, my battery drained crazy fast! I did a ton of research (which I will be posting soon), and found out that the reason why my battery was draining so fast was that I had restored it from a previous backup. You must set it up as a NEW PHONE if you don’t want that to happen, which means you will NOT be restoring from a backup. So this app would not work for how I suggest upgrading your iOS device based on my experience, unfortunately.