Blink, which was recently purchased by Amazon, is a battery-powered indoor security camera that's designed to last for as many as two years before it needs new batteries. 

Price: $99, which roughly converts to £75 or AU$125. The starter kit includes a Sync Module

The Tend Secure Lynx has 1080p HD live streaming, seven days of free motion-based video clip cloud storage, and facial recognition.

Price: $60 (£45, AU$80).

Blink's Video Doorbell is one of the most affordable smart buzzers we've come across. This battery-powered doorbell is supposed to last for at least two years before you need to replace its AA lithium batteries. 

Price: $99 (about £75 or AU$125) if you already have a Blink Sync Module

Reolink's Argus is an outdoor camera powered by four CR123A batteries. Rather than relying on cloud storage, this security camera has a microSD card so you can save footage on it.

Price: $100, which converts to roughly £75 or AU$125.

Guardzilla is a quirky-looking security camera with a built-in microSD card for local recording, a 640x480 VGA standard-definition resolution and an 89-degree horizontal field of view.

Price: $100 (roughly £75 or AU$125 converted).

iSmartAlarm's Spot is a cute little camera at a good price. It's supposed to identify the frequency of a smoke detector and alert you if there's a problem.

Price: $99 (roughly £75 or AU$125 converted).

The Ezviz Mini 360 Plus has a 340-degree panning angle 1080p HD live streaming. It also works with IFTTT and offers two-way audio.

Price: $80, which converts to roughly £60 or AU$100.

The Blink XT Outdoor Camera is the weatherproof version of its original indoor cam. Like the indoor model, the XT Outdoor is battery-powered.

Price: $100 (about £75 or AU$125) if you already have a Blink Sync Module

Not only does Yi's 1080p Home Camera have high-definition live streaming, it's also supposed to distinguish between a baby crying and other sounds.

Price: $60, which converts to about £45 or AU$75.