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.

Whenever the time comes around to upgrade your phone, tablet, or laptop, you don’t necessarily have to go for the latest (and most expensive) model. You can take the refurbished route instead.

Refurbished tech sits somewhere between brand new and used, although the exact definition depends on where you’re buying from. Typically, these devices will have been returned after a certain period of use, though the length of that period and the extent of the use can vary from gadget to gadget.

What you always get with refurbished devices is a guarantee that they’ve been professionally inspected, cleaned up, and (where necessary) repaired. They’ll come with a warranty of sorts too, so you can be confident they’re not going to fail out of the box. They are often a year or two (at least) behind the latest gadget releases as well.

Crucially, these items will cost you significantly less than buying new, and there’s a good chance they’ll last almost as long too. At the very least, it’s worth looking around to check out current models and prices—here’s how to do it.

The best refurbished tech you can buy

Phones are pretty much the perfect gadget if you’re wanting to take the refurbished route. A constant, annual cycle of new models hitting the market means old models being sold on, and lots of different places to buy from. Any refurbished marketplace you come across will likely have a phones section. You can throw in tablets here too, which are again regularly updated and widely available.

What’s more, year-on-year phone and tablet upgrades are more iterative than they used to be. You’re not really missing out too much by having a phone design or a tablet spec that’s a year or two old—these devices are well supported with software updates for many years by Apple, Google, Samsung, and other manufacturers. That means you don’t need to worry about your refurbished bargain becoming obsolete soon after you’ve bought it.

Laptops are another product category well suited to being refurbished. There’s an even greater choice than with phones and tablets when it comes to specs, designs, and screen sizes, which means you’re likely to be able to find something that fits your requirements without too much searching. 

Games consoles can be bought refurbished too. Here the refresh cycle is much slower—there were seven years between the PS4 and the PS5, and we’re still waiting for the PS6—so you’re not really buying outdated tech, just pre-owned. Older consoles often show up on refurb portals as well, if you want to do some retro gaming.

The tricks to finding a good refurbished gadget deal are all common sense: Buy from a reputable outlet (see below), look particularly closely at the details given for the item condition and the included warranty, and shop around several sites for the best deal.

Give some thought to timing as well. Phones in particular are usually released on a predictable schedule—Google, Samsung, Apple, and others all tend to launch new handsets at the same time each year. So if you’re hearing rumors about product refreshes, you might want to wait until they’ve arrived. It’s always going to have a knock-on effect on the refurbished market, and you might be able to get a later model.

Where to find the best refurbished tech

There are plenty of places to find refurbished tech online, which tells you that plenty of shoppers see the appeal—and gives you the chance to compare prices and save as much money as you can. To begin with, Apple, Google, and Samsung all have official stores for refurbished tech, with one-year warranties as standard.

If you’re looking at third-party refurbished tech stores, BackMarket has one of the widest range of gadgets. You’ll find phones, tablets, laptops, consoles, speakers, headphones, smartwatches and more here, and some significant discounts too. As well as a one-year warranty as standard, the site also has a free 30-day returns policy, in case you change your mind about what you’ve bought.

Don’t discount eBay from your searches either. Yes, there are lots of individuals selling old tech here that’s way past its best, but there are also real manufacturers and reliable third-party stores selling refurbished kit through the portal too, covering every category you can imagine—one way to get started on your refurb search is to click the Brand Outlet link at the top, though you can also run a general search.

Then there’s Swappa, which is another well-respected source of refurbished gadgets. It has a mix of used and refurbished items, and a mix of individuals and professional tech sellers, so be sure to read the listings carefully to know what you’re getting. Reassuringly, all the listings are reviewed by Swappa staff, and the condition of gadgets (plus details of any warranty) have to be clearly stated.

Also worth a look is Amazon Renewed, especially if you’re already used to the Amazon shopping experience, because everything works in the same way. The condition of items and the warranties attached to them can vary, but everything comes with a 90-day guarantee window for returning items if you need to.

Ideally, it’s best to be checking multiple different sites in your search for the best refurbished tech—there isn’t the same consistency of pricing as you’ll find on something that’s brand new, so you can compare different offers against each other (just be sure to check on what else you get for the price, in terms of returns policies and extras).

The post The best refurbished gadgets to buy (and where to find them) appeared first on Popular Science.

Whether you’re on Windows or macOS, a desktop or a laptop, you’ve got options when it comes to how your computer uses power. On laptops, these can help you save battery life; on desktops, you can save energy and reduce your electricity bill.

It’s therefore worth familiarizing yourself with the options and what they do, so you can make the most of them. You may have always left the defaults in place and never considered making any changes—but here we’ll set out the settings you’ll see in your operating system.

These settings apply to the latest versions of Windows 11 and macOS 27 Golden Gate at the time of writing. If you’re using older or newer software, the screens may differ.

Microsoft Windows

You can find the power options in Windows by opening up Settings from the Start menu, then choosing System > Power (desktop) or System > Power & battery (laptop). At the top, you’ll see Energy recommendations, which should put your system in the most energy-efficient mode—you can use these recommendations as quick shortcuts to the best settings, if you’d like.

Then, from the top, we’ve got Power Mode first. This gives you three choices for both battery power and when your system is plugged in or charging (on a desktop you’ll obviously only see the latter). Best Power Efficiency, Balanced, and Best Performance let you choose how Windows balances power demands and system performance, with Balanced as a decent compromise.

Next up is Screen, sleep, & hibernate time-outs. You can choose how long Windows waits before these modes kick in, both when your system is plugged in and (if you’re on a laptop) when you’re running on battery. In all three cases, shorter time-outs mean less energy usage.

Then there’s Energy Saver, which puts your Windows system into an economical, low-power mode. Background activity is reduced, display brightness is dialed down, updates are paused, and some visual effects are disabled. On a desktop or laptop, you can toggle this on or off manually, and on a laptop you can also set it to turn on automatically when your battery gets down to a certain level.

The last entry here you need to know about is Power & sleep button controls, which set what the physical buttons on your computer do. Make sure these are configured in the way you want—so you’re not, for example, thinking that you’re fully powering down your laptop or desktop when you’re actually just putting it to sleep.

Apple macOS

Over on macOS, the desktop and laptop separation is more distinct. Open up System Settings from the Apple menu on a desktop Mac and you’ll see an Energy menu, whereas if you do the same on a MacBook laptop you get a Battery menu.

The options are broadly similar, although on a laptop you’ve got battery-usage statistics and a choice of configurations for both battery and plugged-in power. The first drop-down, Low Power Mode, reduces some background activity, dims the screen, and applies a few more tricks to reduce energy use.

Some Macs—primarily those with the latest, fastest Apple Silicon processors, also offer you an Energy Mode drop-down. From here you can choose your preferred balance between power draw and Mac performance, and the options are Low Power, Automatic, and High Power (on a laptop, you can have a different setting depending on whether your MacBook is charging or not).

Behind the Options button there are a few more settings you can take advantage of, including one for preventing the system from automatically going to sleep when left idle, and (if you’re on a laptop) dimming the screen and optimizing video streaming performance when you’re on battery power. Again, these let you choose the mix you want between performance and energy use.

The screen time-out settings aren’t here; they’re actually under Lock Screen in System Settings. You can set the delay between your system being left idle and the display turning off, and the shorter that delay, the less power your Mac will be drawing (though with a really short delay, you’ll find the screen turns off when you’re still looking at it).

The post These are the best power settings for your Windows or Mac system appeared first on Popular Science.