Not only ibilik, you can also try nestia, propertyguru.com, flatsdb, 99.co etc., plenty of sites out there.
But since you're starting work in Sept, perhaps, wait until the 3rd week to start finding.
Many agents won't bother responding to you if too early. Too early as in 1 month early.
Also, you should allocate at least one day to go and view the rooms in SG.
Photos sometimes doesn't show the real condition of the unit.
When you go and view the rooms in SG, prepare some cash to pay deposit (usually 1 month).
This saves the hassle of having to TT the money to agent later.
If you want, I can recommend a good agent to you.
Can try and whatsapp this agent.
hi, is it normal for foreigners like us to use agent to find our 1st room there?