According to Timatic, the tool used by airlines to check document requirements (courtesy of Emirates), you do not need a visa to enter the Philippines. Note that having the visa by Singapore exempts you, with no other conditions such as its use.
Nationals of India traveling as a tourist with a passport valid for a minimum of 6 months beyond the period of intended stay, for a maximum stay of 14 days. They must have a valid tourist, business or resident visa issued by Australia, Canada, Japan, Singapore, USA, United Kingdom, or a Schengen Member State .
Length of stay is calculated by starting on the next day after the day of arrival in the Philippines.
Extension of stay possible for an additional 7 days, for nationals of India entering the Philippines when holding a valid tourist, business or resident visa or permanent residence permit issued by Australia, Canada, Japan, Singapore, USA, United Kingdom, or a Schengen Member State .