A new social media app that lets people post anonymous questions – and answers – to fellow Snapchat users has become the most downloaded iPhone app in the UK and America just a week after its release. 

But it’s also brought with it concerns from parents about the possibility that some users may use Yolo to “bully or abuse” children. 

The NSPCC’s Andy Burrows told the BBC that apps allowing anonymous comments could be “easily misused” to send “abusive or upsetting messages”.

“Snapchat should justify how this app meets their duty of care to children,” he said.

The app is rated 12+, which the US-based child safety campaign group Protect Young Eyes has branded “too low”.

“Anonymity has always created a breeding ground for hate and very poor teen decision making,” the organisation said.

“Do you know many 12-year-olds who consistently make great decisions over the long haul without accountability? Neither do we.”

[Read More: Even Teens Think They’re Using Social Media ‘Too Much’ – Here’s Why That’s A Good Thing]

Yolo works using your Snapchat login, as the website TechCrunch explains. You can add an “ask me anything” or “send me anonymous messages” sticker to your Snapchat Story – which can be sent either to specific contacts, or shared more widely. 

It was built using Snap Kit – a software creation platform launched by Snapchat last year – and created by the French start-up Popshow Inc.

A spokesperson from Snap Inc, the company that owns Snapchat, told HuffPost UK: “While Yolo is not owned or affiliated with Snap in any way, we believe that privacy and security are essential to honest self-expression and this philosophy is key to every product that we create,” she said.

“Our Snap Kit partners agree not only to our privacy policy, but also our community guidelines which clearly lay out behaviour and content that isn’t tolerated on our platform.

“Bullying, harassment and intimidation are a direct violation of our Community Guidelines and Terms of Service, and we urge any Snapchatter receiving messages like this to report it to us immediately through our in-app reporting tools.”

Yolo founder, Gregoire Henrion, told TechCrunch he had not expected the app to be so popular. “It was not supposed to be a success,” he said. “It was just for us to learn. It went 100% viral.”

[Read more: Cyberbullying Advice For Parents: 7 Signs Your Child Is Being Bullied Online]

According to reviews on the Apple App Store, some users received messages “wishing them dead”, while others had been called names such as “weirdo”.

One user wrote: “People will get bullied in this – it’s not a good idea.”  

There are concerns that Yolo may follow in the footsteps of similar Q&A apps such as Ask.fm, Sarahah and Whisper, which have been accused of facilitating cyberbullying. 

So, as a parent, what do you do if you’re concerned about how your child is using apps like these?

Here are some tips:

1. Know the age ratings

Yolo is aimed at kids aged 12+ but some users suggest your child may benefit from being older than that. If your child is younger, perhaps they shouldn’t be using it. 

2. Read the privacy policy

It’s worth checking out the fine print. Yolo says it may access your contact list, and will collect information about content you post, including groups you belong to, interactions with friends and live videos.

3. Turn off the App store

If you don’t want your child to download Yolo or similar apps, turn off access to the App store. Protect Young Eyes says: “It’s so simple and still not enough parents keep the App Store turned off. And, since kids are given the opportunity to invite other kids to “get the app,” unless you have it turned off or set up with Family Sharing, chances are at least one person they’re following will blanket their contacts with an invite.”

4. Talk to your kids about bullying

It seems simple, but warn your child of the dangers of being bullied – or bullying – online. Read more here about what to do if your child is the victim of cyber-bullying. If you’re struggling to work out how to have certain types of conversation, look at Thinkuknow. The website is connected to police and CEOP and offers advice that’s targeted appropriately to the age of your child. 

5. Understand technology

If you’re baffled by apps and social media, have a look at parent forums such as Parentzone, which has sections ranging from explaining Fortnite, to what game age ratings really mean and how to achieve a family-wide digital detox. 

6. Report Any Serious Risk of Harm

Take a look at the CEOP online safety centre. You can make a report to one of CEOP’s Child Protection Advisors if you are worried about online sexual abuse, or the way someone has been communicating with your child online.  

HuffPost UK has contacted the French start-up Popshow Inc. for a comment in response to the criticism, and will update this piece if they respond.