I have an iPad and an iPhone but I don't want the same apps on each BUT whenever I plugged either in to sync they automatically download all the apps it's really frustrating. Please help
Create two different libraries. One for each device. When opening iTunes, hold the shift key down and a prompt will come up asking you to select the library that you want. These libraries are usually stored in the Music folder.
Click on your iPad in the left pane of iTunes, then click on the Apps tab. Under the list of available apps, there is a check box. Uncheck, and repeat for your iPhone.
This should prevent apps being automatically installed.