hello! i had the same problem and cos I updated my mac and windows PC, the itunes method doesn't work anymore.
i've contacted apple support and got the following response which solved my problem:
- download evernote to your iphone with the latest iOS
- using the same itunes account, login to your apple ID on your ipad 3
- go to purchase history
- you will be prompted to download the last compatible version of the app.
hope it helps!