If you have a lot of apps in your App Store purchase list in your ipad / iPhone then you might want to delete some of the apps that you either no longer use, or that you downloaded once to try out and found they were no good!
There used to be a way to do this from the iPhone or iPads built in App Store app, but this was removed in iOS 6
There is a workaround though.
1) open iTunes on your mac or PC
2) go to ‘store’ in the side bar on the left
3) go to ‘purchased’ on the right bar
4) you can now navigate to apps
5) if you hover your mouse pointer over the app icon, a small x appears.
6) once you click this then it will no longer appear in your iPhone or ipad!!