You can also connect to sg.linkedin.com

Linkedin is a social Media website for Professional People.
It does not list Singapore phonenumbers like historic Whitepages
but profiles of individual people.

Connected to Linkedin you can send messages
to people from Singapore you found.

2016 Linkedin was acquired by Microsoft.

As of 2020 August 2.918.000 people from Singapore
are connected to Linkedin.

More on the history of Microsoft
on the Brand Portal VB.com