How to transfer application data from iphone

Question

Hi,
I've recently had to reload my windows PC meaning that I've a brand new itunes installation. I've just downloaded a satnav app I'd like to sync to my iphone.
The problem is that there are loads of apps on my iphone and if I click the box to sync the iphone with itunes it says that all existing applications and their data will be replaced on my iphone. I have transfered the purchases so I should get all the apps back but I don't want to lose the data.
Is there any way I can backup the data in these apps or selectively sync the satnav app?
Cheers
-Al

Answer 1

If you included your iTunes library with your computer's backup before reloading Windows (the iTunes named folder which stores all iTunes data) and placed the iTunes folder in the designated location - the same location before reloading Windows, you would not have to re-install all iTunes content including 3rd party apps.
You can't selectively install the satnav app from iTunes on your computer without all iTunes content on your iPhone being erased first, but you can download and install the app with your iPhone.
Application settings and data created and stored by a 3rd party app is included with your iPhone's backup.
With your iPhone connected to iTunes, control-click on your iPhone in the iTunes source list and at the menu window that appears, select Back Up.
After all iTunes content on your iPhone is erased when syncing and the 3rd party apps are re-installed, if 3rd party app settings and data created and stored by a 3rd party app is lost in the process, and I think it will be, you can follow this by restoring your iPhone with iTunes from your iPhone's backup. After the backup for your iPhone is restored, this must be followed by a sync to re-transfer your selected iTunes content including 3rd party apps. The 3rd party app settings and data created and stored by a 3rd party app will be restored with your iPhone's backup.