At the beginning, we are so excited to download many apps to iTunes, after a period of time, we will be boring apps pane in iTunes getting increasingly cluttered, so we must clear up the unwanted apps and make it clear and tidy.
The key problem is that if you delete an app from your iDevice, the app remains listed in iTunes. This is good if you might one day want to redownload it, but it creates a rather lengthy and unmanageable list when you go to sync your phone. In my case, if you have more apps in the Sync Apps list in iTunes that are no longer installed (unchecked) than those that are, making it a chore to sort and manage the apps on your iPhone and iPad.
When viewing the apps on your iDevice in iTunes, you can check and uncheck apps from the Sync Apps list to add or remove them from your iDevice when you sync next. If there are apps listed that you know you’ll never return to, you’ll notice that there is no way to delete them from this list.
If you click Apps under the Library header in the left panel of iTunes, however, you’ll be able to permanently delete apps, removing them entirely from iTunes. Highlight an app’s icon or a group of icons by holding down Shift and hit the delete key (or select Edit > Delete from the top menu or right-click on an icon and selecting delete).
Step 2: to remove all files associated with the apps you selected for deletion, click Move to Trash on the next window.
After you deleted the unwanted app from iTunes, then you have more space to storm movies and musics, to for this M4V videos, if you need convert to Kindle Fire or Nook Tablet for playing, you can use the powerful iTunes to Kindle Fire Converter Mac or iTunes to Nook Tablet Converter Mac.