In order to restore your Tab Pro subscription on iPad please take the following steps:
1. Open the app
2. Press "Account"
3. Sign in with your Ultimate Guitar account
If you didn't have Ultimate Guitar account:
1. Open the app.
2. Tap on the "Subscribe now" button on the home screen.
3. Tap on the "Restore" button and enter the same Apple ID, that was used for purchase.
Your Apple ID is not the same as your Ultimate Guitar account, please don't confuse them. Also, your Apple ID password is not the same as your Ultimate Guitar account password. If you don't remember your Apple ID password, please use "Forgot Password" option in your Apple ID account. If you don't remember your Ultimate Guitar account password please refer to the following article: http://support.ultimate-guitar.com/knowledgebase/articles/514271