This free windows app PhoneClean enables one to free up valuable disk space of your phone or ipad. It works its magic by removing long-term caches, cookies, and temporary and junk files generated by many apps or the result of failed iTunes syncs.
(http://asset0.cbsistatic.com/cnwk.1d/i/tim/2012/08/28/PhoneClean_01_460x329.PNG)
image by Matt Elliott/CNET
After connecting iPad or iPhone and launching PhoneClean, It presents a simple three-step process: connect, scan, clean. Follow the procedure and reclaim storage space on your iOS devices.
Below is another snapshot by cnet of how the scan report look like. Try this, it works.
(http://asset0.cbsistatic.com/cnwk.1d/i/tim/2012/08/28/PhoneClean_iPad_2_460x329.PNG)
by Matt Elliott/CNET