The Republic of Singapore Aero Club is active at Seletar; operating, when I was last there, a couple of Aerospatiale TB9, TB10 aircraft. There are a few private owners mainly with higher powers singles and twins.
Local flying is somewhat restricted (its the only place I've had to file flight plans and hand in my passport to airport security to fly circuits!) so many flyers commute across the Causeway to Johor Bahru in Malaysia to fly in the more relaxed GA environment there.
Bear in mind it is hot and thermic and due to smoke haze visibility for VFR flying is often poor by European standards - and you certainly don't want to mix with 38,000 foot CBs, so your flying remains weather-regulated. So saying there are cracking fly-out destinations such as Tioman Island, where a five-minute walk from the airport takes you to an idyllic tropical beach and seafood restaurant!