One of the creators of a new sexual consent app is defending his invention from criticism.

The app, Legal Fling, allows people to agree to getting intimate, before selecting yes or no to different categories like using condoms.

It's sparked concerns that sexual predators will abuse the technology and help them protect them from rape allegations.

But co-founder Arnold Daniels told Nadine Higgins participants who have signed on are free to change their minds.

"The contract on itself is not the consent and it's not the proof that you have consent. The contract is about making the rules very clear."

The Dutch creator said people need help when it comes to outlining their boundaries.

"The world is changing. Talking with somebody that may be a little uncomfortable is a big step for people."

The app was criticised earlier this week by Shine director Jill Proudfoot, who said the app would provide evidence someone had consented even if they changed their mind.

"Someone might consent early in the evening to particular behaviours and then decide they don't want to do that, and then it's forced upon them but the person forcing them has evidence that they have consented."

LISTEN TO ARNOLD DANIELS TALK WITH NADINE HIGGINS ABOVE