When it comes to the mobile app heavyweights, few can beat WhatsApp. It’s estimated that around 3 billion people now use the cross-platform messaging tool at least once a month. And it’s important to remember there are only 8 billion or so people on the planet, so there are no signs of its popularity waning anytime soon.

Beyond being a hugely successful app, it’s also packed with features. You can use it to chat, make voice and video calls, share files, broadcast your location, and more. Even if you’ve used WhatsApp for years, you might not have discovered everything it’s capable of—which is where these tips come in.

1. Set a timer for messages to disappear

You don’t necessarily want everything you say on WhatsApp to be remembered forever, and the app includes a timer feature that will automatically expunge messages in a chat 24 hours, 7 days, or 90 days after they’re read, unless you specifically keep them. This is set on a chat-by-chat basis, and affects everyone in a conversation.

To change the setting for one of your chats, tap the contact or group name at the top of the screen, then pick Disappearing messages to select your time limit. This is applied until you turn it off or select a different period, but doesn’t affect the conversation history.

2. Lock away your most sensitive chats

Another way of protecting sensitive information in chats is to add an extra lock to specific conversations. Even if someone should gain access to your phone and your apps, they won’t be able to see your locked chats.

From inside a conversation, tap the contact or group name at the top, then pick Chat lock (Android) or Lock chat (iOS). You can then use a specific PIN code to block access to the conversation, or use the same biometric scan technology (such as Face ID) that already protects your phone at the lock screen.

3. Edit a message after sending it

Have you noticed you can edit messages after sending them? It’s handy for those typos you only spot after dispatching a message—long-press on whatever you just sent, then tap the three dots and Edit (Android), or just Edit on the pop-up menu (iOS). Modified messages have an ‘Edited’ label visible to everyone in the chat, but they won’t be able to see what the original message said.

4. Stop specific contacts from seeing when you’re active

WhatsApp can tell your contacts whether you’re currently using the app and when you were “last seen,” but this might not be information you want to share with everyone. As well as disabling the feature entirely, you can also turn it off for specific contacts.

Open the You tab, then tap Privacy > Last seen and online, then select My contacts except … under the Who can see my last seen heading. You can then pick the contacts you don’t want to give this information to, and set the Who can see when I’m online option to match the same list.

5. Pin important messages you need to refer to or remember

Important details can quickly get lost in WhatsApp conversations, especially in busy group chats. But there is a way to pin specific messages to the top of the chat so they’re easy to get back to—someone’s address or the start time of an event, for example.

To pin a message on Android, long-press on it, then tap the three dots (top right) and Pin. On iOS, long-press a message and choose More > Pin. You can have up to three pinned messages per conversation, and select from three options for how long they’re pinned for: 24 hours, 7 days, or 30 days.

6. Give contacts their own notification sound

WhatsApp lets you assign specific notification sounds to specific contacts, which means you know who’s calling or messaging without picking up your phone. It gives you a better idea of whether something needs attention right away or can be safely ignored for a while.

Tap the group or contact name at the top of a chat, then pick Notifications and Notification tone or Ringtone to make changes. You can also select Vibrate to customize vibrations for each chat, though there are only four options here.

The option to mute the conversation is on the same screen—you can set mute separately for calls and messages.

7. Message yourself with notes and reminders

Not all messaging apps let you have a conversation with yourself, but WhatsApp does. This might seem like a rather pointless (and lonely) way of using the messaging app, but it can be really useful for jotting down things you need to remember on the go, leaving yourself voice notes of ideas and thoughts, and so on.

From the main conversation list, go to start a new chat, then search for “you” as the contact (or just enter your own username or phone number).

The post WhatsApp like a pro with these 7 expert tricks and hidden features appeared first on Popular Science.

We’re very much in the era of smart glasses now, with the necessary tech components small and light enough to be put into a pair of spectacles. Meta just unveiled a fresh batch of Ray-Ban glasses; numerous smaller companies are producing their own models; and the rumors are that Apple is planning a launch in this category too.

In some ways, the appeal is easy to see. These specs can pipe music, audiobooks, and podcasts right into your ears; answer questions about anything (and anything you see) through onboard AI assistants; and offer convenient, hands-free photo and video capture.

Whether you’re racing down a hill on a mountain bike or opening presents with the kids, recording what’s happening with a pair of smart glasses is a lot easier than it is with a phone. You can keep gripping the handlebars, or just stay more present in the moment, while still grabbing some memorable images and video clips.

The problem is that this convenience extends to anyone who wants to capture recordings in a more surreptitious manner, without holding up a smartphone. While all the smart glasses from mainstream manufacturers have recording lights, they’re not always easy to see and can sometimes be tampered with.

That’s led to a growing backlash against the tech. Despite all the advantages of these devices, people are very wary of being recorded without their knowledge, and while there isn’t yet any related legislation, we’re starting to see bans: Smart specs are now forbidden in New York courts, for example.

There are also now anti-smart glasses apps, which will warn you if there are a pair in your immediate vicinity—and we’ve covered a couple of them below. For those who want to make sure they can tell the difference between smart glasses and just a normal pair of spectacles, these apps can be a huge help.

Nearby Glasses (Android and iOS)

Nearby Glasses is free on Android, iOS, and open source—which means you can see and even adapt the code for yourself—and it’s been around for longer than ZuckOff, which we’ll get to in a moment. It’s polished and regularly updated and does its one job and does it well.

The underlying mechanism at work here is a simple one: It scans the area around you for Bluetooth devices, then uses registered codenames to work out which ones are spy glasses. Every Bluetooth device sends out a code to identify itself, and this is the information Nearby Glasses latches on to.

Via the app’s settings page, you’re able to set how sensitive the Bluetooth detection is, which means you’ll get pinged more or less often depending on how you set it. It’s up to you how wide a range you want to set (the closer the RSSI, or Received Signal Strength Indicator, is, the closer the glasses have to be before they’ll trigger an alert). Alerts can be sent in the background while the app isn’t open, but only on Android.

It’s worth bearing in mind that this is a useful tool but not a guarantee that smart specs will be detected each and every time they’re nearby (the devices may have Bluetooth disabled, for instance). The app also can’t tell you which person nearby is wearing the glasses, so you may have to do some guesswork (or just leave wherever you are).

ZuckOff (Android and iOS)

ZuckOff (Meta’s boss is Mark Zuckerberg, remember) is newer than Nearby Glasses, and is also available for both Android and iOS. That cross-platform support is good to see, but this isn’t open source: Unlocking the full capabilities of the app, which include background scanning and a full history file, costs $14.99 a year or $29.99 for a lifetime of access.

The basics of scanning are free, and like Nearby Glasses, ZuckOff scans signals sent by Bluetooth devices in your vicinity and identifies them using the data they’re sending. You can set the RSSI threshold in the app settings, and you’ll get a breakdown of how near or far away detected glasses are.

ZuckOff can buzz your phone when a pair of smart glasses enters your designated area on both Android and iOS, though it’s a paid extra. One nice touch that is unique to ZuckOff is the ability to register your own wearables so they’re not flagged as a false positive—though presumably if you’re using an app like this you don’t actually have any smart glasses of your own.

As with Nearby Glasses, ZuckOff is more of a guide than a precision tool—it won’t lead you straight to a person wearing smart specs, for example. However, it’s a polished and reliable app that neatly presents all the key information it needs to, and if you can afford the subscription, the history records are worth digging into.

The post How to tell if someone is wearing smart glasses near you appeared first on Popular Science.