He believes the technology could help navigate the way forward as the country confronts an increasing number of sexual assaults while reporting and conviction rates remain low.

Mr Fuller said he had discussed the consent app with Attorney-General Mark Speakman and Police Minister David Elliott.

Read more: NSW top cop wants sex consent law reform

"The conversation around sex and consent seems to be anchored to the '50s and clearly it isn't working," Mr Fuller wrote in an opinion piece published by Sydney's Daily Telegraph.

Consent apps could normalise conversations around consent and formalise the habit of actively seeking consent.

"There is no implied consent. It needs to be positive consent. How do we do that in this day and age? One option is with technology," Mr Fuller said.

"People say 'how unromantic is that'. But think of how many people are looking for friendship and love online - it's not as though technology and dating are foreign to us."

He conceded an app could provide challenges, such as if someone withdrew consent after agreeing.

Mr Fuller told Channel 9 sexual violence was increasing faster than other violent crime, with 15,000 reports in NSW last year.

Offenders were assuming consent when a woman had consumed alcohol "and clearly that can't be the standard", he said.

"At the same time you may have a son or a brother and you think this is too challenging but this app ... protects everybody."

Denmark has already introduced a consent app and expanded the definition of rape to include sex without explicit consent.

The app proposal was met with criticism from some.

CEO of Women's Safety NSW, Hayley Foster, tweeted that it was good NSW Police was acknowledging the need for affirmative consent but that "the abuser can simply coerce the victim to use the app".

NSW Greens MP Jenny Leong, who earlier this week flagged a bill to strengthen the state's sexual consent laws with the key principle of 'enthusiastic consent', criticised the proposal in a tweet.

"We need consent law reform, we need holistic consent education, we need to stop men feeling they are entitled to whatever they want, we need an independent complaints process, we need justice. We need equality. WE DO NOT NEED AN APP!!"

The NSW Law Reform Commission made 44 recommendations to reform consent law in a 250-page report tabled to parliament last November.

The report's recommendations include that consent to sexual activity should not be presumed and that a person should not be seen to have consented because they did not resist physically or verbally.

Australian Associated Press