Clever ways to use your pre-loved gear

If you're a bit of a gadget lover – and even if you're not – there's a fair chance you've got some perfectly functional old tech just lying around the house gathering dust. But while our pre-loved laptops, smartphones and tablets might no longer pass muster as our primary devices, obsolete gear can enjoy a new lease on life when it's re-purposed for simpler tasks.

For example, with the right software, you can turn a tablet into a second computer monitor, make an old PC into a digital hub that you can access and control from anywhere with an internet connection, or even transform your old smartphone into a security camera. If these kinds of revamps sound like labour-intensive DIY projects that necessitate tinkering with wires and cables, guess again: none involve anything more complicated than downloading a few apps, all of which are either inexpensive or free.

Best of all, trying out any of these will help you get more mileage out of forgotten or retired products that you once paid good money for – and that's definitely smart. What is it? Duet Display

How much? $14.99. Pros: When using a desktop or notebook computer, your iPad is probably just lying idle. But with Duet Display, you can actually put it to work at the same time, connecting your tablet to your PC or Mac and using it as a second display, giving you an extra iPad-sized screen to work with. It now supports Apple's Touch Bar too, giving you extra functionality on older Macs.

Cons: iOS only – but other alternatives are available (some of them wireless), which also support Android tablets. duetdisplay.com What is it? TeamViewer How much? Free for personal use.

Pros: There's nothing like getting to work and realising you have left an important file at home. With TeamViewer, you can remotely log into your home PC over the internet (even from mobile devices). Extremely useful, and can be used to turn an old PC into a remote data hub.

Cons: Free for personal use with limitations but you can also subscribe for the commercial version. Also check out LogMeIn, GoToMyPC, Splashtop, Chrome Remote Desktop, and many more. teamviewer.com What is it? Manything How much? Free for basic plan.

Pros: Manything (short for “monitor anything”) basically epitomises the idea of revamping old tech, letting you use the camera on iOS and Android devices as a remote security camera and motion detector. Great for peace of mind while you're away from home or for keeping tabs on your pets while you're at work.

Cons: Free plan offers live streaming and motion alerts for one device but you'll need to subscribe to record your security camera footage in the cloud. manything.com