Cove, I buy the Woollies egift cards from cash rewards (most recently at 5.75% off face value) in $500 maximum face value and they have an app I can load them into. Very easy to keep track of and pay with at the checkout.
Might Coles have something similar? I've only ever bought physical DJS & MYR cards. Interested if they have something similar.
There's no app for Coles gift cards. The Woolworths Money app which tracks Woolworths Wish cards is great as others have mentioned.