Hi Junshong,
You can find a list of mobile-supported wallets here.
http://bitcoin.org/en/choose-your-walletLast time I visited Singapore, people were still generally relying on the same types of mobile phones as the rest of the world.
Asia Nexgen
ANX.HK+1
Get a mobile wallet and then buy some bitcoins from
localbitcoins.com.you can buy in Singapore from
http://www.ecurrencyzone.net/buy.php#2 ..they always have a option to buy through cash deposit machine even if you are not resident in Singapore.