Peeple will allow members to give star ratings to people they know via the app, much as restaurants and hotels are rated on sites such as Yelp.
The app has caused uproar online, with web users describing it as “creepy” and “terrifying”.
Peeple’s founders say they will pre-screen for negative abuse.
However, users will not be able to delete comments made about them. Nor will they be able to remove themselves from the site once on it.
Among those raising concern was University of East Anglia law lecturer and privacy advocate Paul Bernal.
“The bottom line is this is extremely creepy,” he told the BBC. “It is an ideal trolling tool.”
Mr Bernal added that he was sceptical that the app could ensure users knew the person they were rating.
“How are you determining whether somebody knows somebody?” he asked.
“If you’re using Facebook friends, do people really know all their Facebook friends? Absolutely not.”
Legal ‘headaches’
There may be legal difficulties too, according to Steven Heffer, a partner at the law firm Collyer-Bristow.
“I can only see a lot of headaches,” he told the BBC. “It looks to me like potentially a recipe for a legal disaster.”
Mr Heffer said the app was different from existing social media in that it specifically encouraged users to assess others and that negative comments on individuals would be difficult to police.
“They can’t be judge and jury, can they?” he said.
“They might have some kind of safety net, but it’s not going to stop people being defamed and suffering damage as well.”
The website for Peeple says that negative reviews will be stalled for 48 hours before being published, so that they can be checked by the person being rated.
However, if they are not able to resolve the comment with the person making it within that time, it will go live anyway.
This system could be problematic if someone did try to bully another person via the app, said technology researcher Natalie Kane.
“Essentially you’re asking victims to confront their abusers – that’s a difficult conversation for any victim to have,” she said.
‘Natural fear’
Peeple co-founder Julia Cordray told the BBC: “With any new concept there is naturally fear.
“When the people found out that the Earth was round instead of flat and that we revolved around the Sun instead of the Sun revolving around us, naturally people were upset and confused and they pushed back with all that they had.”
Ms Cordray said the app, due to launch in November, had 5,000 members signed up for testing and was receiving more than 100 requests every hour for access.
She said Peeple would independently assess negative reviews during the 48 hour window to ensure they did not breach terms and conditions.
These include a ban on:
profanity
degrading comments
abuse
sexual and legal references
racism
hateful content
Ms Cordray added, “We are not anonymous. You have to be 21 and older. You can only message someone once, and if they don’t respond you can never message them again.
“You can share the positive things that you say about people or the positive things that people have said about you through our sharing features.”

source: bbc