It seems Grabfood is aggressively fighting for market share, giving very generous $8 Promo Code currently: 8TASTY.
New users of Grabfood can use the Promo Code 8TASTY twice. The current delivery charges are $3-$5 depending on surge. That means you can get a $3-$5 free meal delivered for free to your home. E.g. Bubble Tea or some McDonald’s food.
There is also another Grabfood Promo Code (also $8): CHILLOUT
The “CHILLOUT” Promo code is limited to a one-time use per eater and is only valid from 13 to 14 October 2018.