This seems to work fine through the website on first purchases too currently
Greetings everyone, just saw this on the Amazon website!
Use APP15 within the Amazon app to get $15 off eligible purchases.
eligible order on the Amazon App
The promotional code entitles any new or existing customer of amazon.com.au who has not previously made a purchase on the Amazon app (from the Australian Amazon store) to $15 off their first purchase when they spend over $49 on eligible items via the Amazon app. For the purpose of these terms and conditions "eligible items" refers to any item sold by Amazon AU through the Amazon app.
Eligible items excludes products sold by third party sellers (including Amazon US and even if fulfilled by Amazon AU), digital purchases such as e-books, subscriptions such as Prime video and audible, gift cards and postage or delivery rates
This should also stack fine with other discount, such as the 20% off $50 spend on everyday essentials.
Cashback does not apply from any provider as they don't track Amazon App purchases
As always, enjoy!
Click the Related Deals Tab to see all APP15 deals.