Hi did anyone tried applying it I saw it is 1.6% cash back with no minimum spending. Also how does the cash back works?

Citibank cashback+ offers 1.6% cashback with no minimum spend and cap.

For the cashback, you can accumulate the cashback and redeem it at one go or you can redeem on a monthly basis depending on your preferance. You can redeem the cashback via SMS.

Like what Yang Teng mention, they are currently having a promo from now till 31 May where you can get up to 4.5% cahsback. Do note that for this promo you will have to apply directly on Citibank website and not 3rd party sites.

There's no spending requirements and cap to the cashback of 1.6%.

They are currently having a promotion now. From now till 31 May 2020, get 4.5% cashback on up to S$5,000 spent in the first 3 months. This means you can earn up to $225 from cashback.