Fake calculator apps: What they are and how to spot them

Emily Lawrenson

Emily Lawrenson

Qustodio writer

Tips to help your child stay safe during the back to school period
Children seeking to keep things private is nothing new – but did you know that now, there’s an app for that? Secret vault apps have been around for years, but children are now using them to store personal, private information that could even have legal consequences if found. Here’s everything you as a parent should know about calculator vault apps, what using them means for your child, and how to spot a fake calculator app on your child’s phone.

What are calculator vault apps?

Calculator vault apps are secret apps that can be installed on a smartphone or tablet, which are designed to look just like a regular calculator application on the surface. Most calculator vault apps can be used as a calculator would be, providing normal mathematical functions such as subtraction and multiplication. 

There are many different versions of calculator vault apps now available for download, but they all have one thing in common: their goal is to act as a front for private images and files. Users can upload secret pictures and videos to calculator vault apps, hidden behind a password. In order to access these private files, the user enters a password into the calculator, which they will have established at setup. This allows them to access the private files inside and upload new files that the user wishes to keep a secret. 

Why kids use fake calculator apps

As we live in an increasingly connected world, helping children stay safe by monitoring their online activities is something most parents now do regularly. As a natural consequence, some children may feel that their privacy is being invaded, and they may look to calculator vault apps as a space to hide the images and files that they don’t want people to know about – either parents, friends, or siblings. Adults could easily use them too, to hide pictures that they don’t want others seeing in their camera roll, for example. 

While this might sound innocent in practise (everyone feels the need for privacy), many of the images that are uploaded to calculator vault apps are sexual in nature. Sexting is becoming a more common practice among young people today, with 14.8% of 11-17 year olds having sent a sext, and 24.7% receiving one. Calculator vault apps offer a place for young people to hide nude pictures, screenshots of sexting conversations, contacts they don’t want you to see in their address book, and even apps that they can use to send sexts.

In addition, some calculator vault apps use the phone’s camera to take a snapshot of an “intruder”, should an incorrect password be entered. This snapshot is stored in the vault to show the user who has been trying to access their files. 

Are calculator vault apps safe?

There are many developers out there making calculator vault apps available for download, so it’s difficult to understand which ones really help keep data and information secure or not, as their individual use will vary. It’s worth reminding your child that nothing uploaded to the internet is 100% safe and secure. There have been cases of users being locked out from their vault app and unable to retrieve private images, as Apple and Google crack down on developers.

In addition, the very nature of calculator vault apps renders them unsafe for children, as they may be using them to hide sexual images. Under 18s are not able to give consent for their naked image to be created or shared, so if they have one on their phone, stored in secret, this is against the law. Children may not understand the severity of taking and sharing nude images, or engaging in sexting, so whether you suspect your child is using a calculator vault app or not, it’s a good idea to speak about consent and online activity with your child, to help them understand the implications of their behavior online. 

Technology tips to help with the back to school routine

How to spot a fake calculator app

There are several things that might help you to spot a fake calculator app if you’re concerned your child is using one.
1. Check the app memory size

Because calculator vault apps look like a regular calculator, it’s very hard to tell just by looking at the icon. One of the best ways to check if the calculator installed on your child’s phone is real or not is to check the calculator’s memory size. If the app is larger in size than 30MB, it could be a signal that the calculator is in fact a vault app.  

How you do this depends on the type of phone: on an iPhone, you can head to Settings > General > iPhone Storage. On an Android, you’ll find it listed under Settings, where you’ll want to check “Storage”.

2. See how many calculator apps your child has on their phone

It might seem obvious, but if your child has more than one calculator app on their phone, one could be a private vault app. However, some children need to use scientific calculators for homework purposes, so the presence of an extra calculator doesn’t always mean there’s something to worry about.

3. Search for the name of the calculator app on the app store

If you can see the name of the app on your child’s phone, look it up. The app description will show you if the calculator is real, or if it’s a way to keep private files secret. 

4. Search for “vault app” on the app store 

Typing in “vault app” on the app store will give you a long list of calculator vault options for download. However, if your child has already downloaded one of these apps, then instead of “Download”, the writing will read “Open” on the app itself. 

If you don’t want to check your child’s phone, and you’re worried about them downloading and using vault apps without your knowledge, here are some of the signs your child could be using a fake calculator app


  • They hide their phone from you when you enter the room
  • They quickly close an app or tab when you enter the room
  • They make regular requests for privacy, which they didn’t make before
  • They are unwilling to show things on their phone or tablet to other people
  • They are suddenly using their device much more frequently

What should I do if I think my child is using a calculator vault app?

If you’re concerned that your child is using a secret vault app, consider making your child’s phone more secure with a parental control tool, or by limiting app store downloads. 

Parental control tools such as Qustodio can help you screen the apps that your child downloads, and offer you insights into the time spent on the apps they already have downloaded onto their phone. 

Above all, it’s important to help your child understand the risks of sharing inappropriate content and what it means for them to engage in sexting. Not all children are aware of what sharing nude images or sexual messages means for them: as it is considered to be child pornography, sending explicit material which includes a minor is illegal – even if the sender is under 18. To help your child understand the consequences of their actions, speak to your child about sexting from an early age. 

To help develop your child’s trust in you, keep family communication open and honest. By creating an environment where your child feels they aren’t judged, and where it’s safe to confide in you, you can encourage them to come to you for advice or seek out your help if they feel uncomfortable online. The more your child feels they can converse with you and rely on you, the less likely they are to want to keep things private – and in turn, see less need to make use of calculator vault apps. 

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