How to delete an app from device using iTunes?

You can delete an app from iTunes by going to the Apps section (from the dropdown on the left), then hit the Delete key. When it asks if you would like to keep the file or move it to trash, choose to move it to the trash.

You can also delete the app directly on the phone and download it through WiFi. Tap and hold the app's icon until it jiggles, then tap on the x to delete it. Next go to the App Store and install the app afresh.

Why are you trying to do this via iTunes? You should delete the app on the phone and use the app store on the phone to re-download it.

However if you feel you must do this via iTunes after you have deleted the app from the phone, go to:

~/Music/iTunes/Mobile Applications

…and delete the application from there.

You can then download it again via the iTunes store and re-synch the phone.

Open iTunes. At the top left of your window, there is a drop down menu, make sure it is set to Apps. You should now see all of your apps in icon form. The tabs below the player window allow you to switch into List view as seen below.

Then select the apps you want to delete, right click and select Delete.