All details in
https://www.citibank.com.sg/gcb/deposits/mxgn-savacc.htm
# Rate is 0.8% * sibor (up to $150k) + increasing counter (applicable to unlimited amount)
# Assuming sibor is 1%
If you open Maxigain account (and fund S$15k from first day of the month),
In first month you should enjoy 0.8%*sibor + 0 (counter 0) = 0.8%
In second month you should enjoy 0.8%*sibor + 0.1% (counter 1) = 0.9%
In third month, 1%
In fourth month, 1.1%
.
.
.
In 13th month, 2% up to S$150k. Amount above S$150k will enjoy 1.2%
That's why @Perisher said it is place and forget account.
Of course feel free to correct me if I am wrong and the last I checked, I don't work for Citibank