http://iscoresports.com/

I recently bought a new iPad and would like to transfer over to it. Do I need to rebuy the App and if so how can I link it to my existing account?

If you are going from one iPad to another, no new purchase is necessary. Just log in to the App Store with the same login you originally purchased with, and the App Store will show iScore as a purchased app available for download.

If you use iTunes backup and restore to the new device, it will automatically transfer your iScore data as well.

so if I originally purchased under my wife's ID I can still transfer to mine?

yes, even if not thru the same ID, you can still do this thru Family Sharing...do a google search for "itunes family sharing" if not familiar.

Though under this scenario, you will probably need FTM to transfer your database to the new device.