Think manhattan got a version for $500 limit.
This is a good answer. The $30K minimum income requirement is a regulatory requirement, but there is an exception for one low credit limit card. There are three such credit cards that I know of that are available to the general working public (non-students):
1. One has already been mentioned: the
Manhattan $500 Card.
2. Another is
Bank of China's F1RST Card.
3. Diners Club offers the
International Ace Credit Card, and it has the lowest minimum income requirement of all ($16,000/year).
It's hard to say which is best. Diners Club has the lowest annual fee ($28), and if you charge $2,000 to the card over the course of a year (average of $167/month, excluding AXS terminal payments) you can get enough Club Rewards points to get a fee waiver -- there are no mysterious fee waiver criteria. Diners Club isn't as widely accepted, although that's probably a very good thing when you're just looking to build a credit history. Diners Club is the only credit card accepted for CPF top ups. BOC's F1RST Card has a
ridiculous annual fee (S$190), although it's waived for the first two years (instead of a one year waiver). It offers the best rebate (0.5%) among these cards. The Manhattan $500 Card has a slightly higher annual fee than Diners, but unlike the Diners Ace you'll never be able to claw back the annual fee via points or rebates. So you're at Standard Chartered's (or BOC's) mercy whether they'll waive the fee or not.
I think I'd go with the Diners Ace in this category, in part because the annual fee waiver rules are transparent and achievable. In this case the limited acceptance is a feature not a bug -- you shouldn't be using a credit card very much (your DBS Visa Debit Card is a much better deal right now, with that 5% rebate promotion still underway), and you should be paying it off automatically every month anyway. This card is just to build a credit history. And it happens to have the lowest income requirement ($16,000/year instead of $18,000).
Sadly, CIMB discontinued its $500 credit card earlier this year (2017). That one was a gem with no annual fees to worry about, ever, for life. For those of you who grabbed the CIMB Classic MasterCard while it was available, you can hang onto it. If nothing else it'll be useful for CIMB merchant promotions in Singapore, and it doesn't cost anything to keep in your wallet.