From time to time, the same promise resurfaces: a app that reveals when a contact is online on WhatsApp, with notifications on your cell phone every time the person opens the messenger, in addition to graphs showing the times when they usually use the device.
Let's start from the end: this type of app is not a productivity tool, it's surveillance—and, in practice, a scam. WhatsApp does not offer this function to third parties; programs that insist on offering it put your number at risk of being banned and your account at risk of theft. In this article, you'll understand how the scam is set up, what Brazilian law says about monitoring someone, how to protect your WhatsApp, and what official alternatives exist.
WhatsApp does not show the status of your contacts.
The "online" and "last seen" statuses only exist within the official app, and even then in a limited way: each user can hide them in their settings. Settings > Privacy. There is no public API that informs a third-party program when a number has entered or left the messenger. The official WhatsApp API is geared towards businesses that serve customers and does not expose third-party activity.
Without this gateway, these apps resort to workarounds. The most common is connecting a parallel session to WhatsApp Web and checking the chosen number every few seconds, recording when the status changes. This blatantly violates the service's terms of use, is unstable, and has almost certain consequences.
What usually happens to those who install
- Number banned. WhatsApp detects automated sessions and blocks the account of the person making the inquiries — that is, your account, not the monitored contact's.
- Account theft. Several of these apps ask you to scan a QR code or enter the six-digit code received via SMS. Anyone who does this is essentially handing over their WhatsApp account to a stranger.
- Recurring subscription. The weekly or monthly charge continues to appear on the card even after the service stops working, and cancellation rarely actually happens.
- Malware. Since they are not accepted in official app stores, these programs arrive as APKs, with a request to disable Google Play Protect — a classic entry point for banking trojans.
- Leaked data. You are providing your phone number, contact information, and payment details to a company with no representation in Brazil and no commitment to complying with the LGPD (Brazilian General Data Protection Law).
Monitoring someone like that is a crime in Brazil.
Monitoring someone else's usage times without their knowledge is not harmless curiosity: it's the construction of a routine profile. When this monitoring involves installing anything on someone else's device or accessing someone's account, Article 154-A of the Penal Code applies, which deals with the invasion of computer devices and provides for imprisonment, increased when there is access to private communications.
Even without technical intrusion, systematic monitoring can constitute the crime of stalking (stalkingThis is a violation of Article 147-A of the Penal Code since 2021. In relationships, this control is recognized as psychological violence under the Maria da Penha Law. Furthermore, the LGPD (Brazilian General Data Protection Law) treats behavioral and time data as personal data, generating civil liability for those who collect it without a legal basis.
How to know if your WhatsApp is being spied on
The most important point is in Settings > Connected devices. There you will see every WhatsApp Web or desktop session linked to your number, with the date of the last access. If there is any entry you don't recognize, tap on it and disconnect immediately — this is by far the most common method used to read someone else's conversations in Brazil.
Other signs of a compromised device: battery draining very quickly, unusual data consumption, apps with generic names that you didn't install, Play Protect disabling itself, and messages marked as read without you having opened them.
How to protect your account
Activate the two-step verification in Settings > Account > Two-step verification Set a six-digit PIN. With it, no one can register your number on another device, even if they have the SMS code. Never share this code with anyone, not even someone claiming to be from support.
On Android, review Settings > Apps, in addition to Security > Device administration apps It is Special access > Accessibility, Remove permissions before uninstalling anything suspicious. Run a scan in Google Play Protect. On iPhone, check Settings > General > VPN & Device Management. If suspicion persists, back up your data and restore your device to factory settings.
What do you really control on WhatsApp?
If the annoyance is the opposite — not wanting them to notice you —, the app itself solves it. In Settings > Privacy > Last Seen and Online, It's possible to hide the last seen time and also the "online" status, limiting its display to no one or only to your contacts. On the same screen, you can disable read receipts, hide your profile picture, and restrict who can see your messages.
It is also worth activating the fingerprint lock In Privacy, turn on disappearing messages in sensitive conversations and use the feature to mute calls from unknown callers.
Legitimate alternatives for every need.
If the goal is to talk to someone at the best time, the method is simple and effective: send the message. WhatsApp delivers it when the person opens it, and the feature of programmed message It exists on various keyboards and in WhatsApp Business.
If the goal is to locate the your own device, use the Find My Device on Android or the app Search on the iPhone. And if the goal is to monitor a child's cell phone, the Google Family Link and the Usage Time Apple does this for free, officially, and transparently, with the child knowing that the feature is active.
Conclusion
None The app reveals when a contact is online on WhatsApp. Reliably, because the service does not provide this information to third parties. What apps of this kind offer is the risk of your number being banned, your account being stolen, a subscription that is difficult to cancel, and exposure to a stalking crime. Closing connected sessions, activating two-step verification, and using WhatsApp's own privacy controls solve much more problems. Questions? Write to [email protected].
Before deciding, check these points.
- What will be monitored. Usage time and location resolve most concerns. Conversation reading is not offered by the official tool.
- If it's an official tool. Google Family Link and Screen Time are free, provided by the operating system manufacturers, and do not require disabling any protections.
- The app is visible on the device. Legitimate tools are kept in plain sight. Those that are hidden are outside the policy of official stores.
- The age of the person who will be accompanied. Supervising a minor child is legal. Monitoring an adult requires free, informed, and revocable consent.
What these tools don't do
Every category has a limit, and knowing this one's limit saves time and money by avoiding those who promise more than what's available.
- They don't read WhatsApp, Instagram, or Telegram conversations: the messages are end-to-end encrypted.
- They are not admissible as evidence when obtained through unauthorized access—illegally obtained evidence is removed from the case file.
- They don't work with just a phone number. Without installation on the device or account credentials, there is no access.
- Installing software on an adult's cell phone without their knowledge is a crime: article 154-A of the Penal Code, punishable by 1 to 4 years imprisonment and a fine.
Frequently Asked Questions
Is there an app that works with just a phone number?
No. It's the promise that identifies fraud most accurately.
How do I know if my cell phone is being monitored?
Check Settings › Accessibility, Device administrators, Data usage per app, and WhatsApp's connected devices.
Is it legal to monitor someone else's cell phone?
Only in three situations: underage child, adult who has given free and informed consent, and corporate apparatus with a written policy.
Which free app is recommended?
Google Family Link on Android and Screen Time on iPhone, both official and free.
Can my boss monitor my cell phone?
Only corporate devices, with a written policy and limited to professional use.
