Mick Fuller said dating apps were bringing couples together and similar technology could be used to provide a digital record of consent.
The senior police officer said the number of sexual assaults reported was increasing and an app could improve poor conviction rates in sex crime cases.
But many people have criticised the proposal as short-sighted and potentially open to abuse.
“The abuser can simply coerce the victim to use the app,” tweeted the head of the state’s domestic violence service Women’s Safety NSW.
“We need consent law reform, we need holistic education, we need to stop men feeling they are entitled to whatever they want… WE DO NOT NEED AN APP!!” tweeted Greens MP Jenny Leong.
Mr Fuller said his suggestion could gain popularity in time.
He said: “To be honest with you, the app idea could be the worst idea I have in 2021, but the reality is in five years, perhaps it won’t be.
“If you think about dating 10 years ago, this concept of single people swiping left and right was a term that we didn’t even know.”