Just saw that this coupon code hasn’t been posted.
As confirmed by Entheogenic it can also be stacked with following
So spend $125 on your first app order with CBA offer and get $55 off (includes $20 voucher from PlusRewards for $4, $30 cashback and $5 off on first app order) - That’s 44% off your order if you spend exactly $125 (additional cost of $4 on Plus Rewards applies)
Mod: Kogan's official wording is Receive a $5 discount off your first eligible order made through the Kogan.com iOS or Android App. Minimum Spend $100. however users have commented that it is taking $5 off every item in the cart.