It runs off the Wear OS operating system and should be compatible with both Android and iOS. You can only use Oppo's HeyTap app if you're on Android, though, at the moment. iPhone users will need to use the Google Fit app instead.

It has a fairly comprehensive set of smart features, including wi-fi connectivity, meaning you can still get notifications when your phone's out of Bluetooth range, provided you're connected to a wi-fi network.For more independence from your smartphone, you can also pay extra for an LTE version. We tested the 41mm version, which has a 320 x 360 resolution colour touchscreen and two physical buttons on the side for navigating the interface.It's nice-looking in reality too - we've tested enough watches to know how flattering promo shots can be - and it feels well-built. Read our full review of the Xiaomi Mi Watch Lite to find out everything we liked and disliked about it. It has a plastic body with aluminum case on the top, to give it a stylish and durable look, looking at the watch, it has a nice display screen a 1.54” TFT LCD, with a 240 x 240 pixel, nothing much action on the outside but under the hood we might see some interesting features with this wearable. As you'll see from the picture, the Amazfit GTS also looks unmistakably Apple-like, with its curved screen and crown, although this crown doesn't rotate like Apple's. Under the Hood – despite its small size, DZ09 do have a micro sim as well as a memory card slot, you can call and receive calls as well as messages right on your smartwatch. It also has a 0.3 MP camera to take photos, but don’t expect too much on a 0.3 MP, you can store the images and photos on the SD card, the smartwatch support up to 32 GB which is impressive. If you are a fitness buff the watch features pedometer and range of fitness features.

The GTS is pleasantly large and scratch-resistant, albeit quite glossy and reflective in bright light, making it harder to read if you're exercising outdoors.Apple Watches have been able to take ECGs for you since the Apple Watch Series 4, so that's a major point of difference between Apple and Xiaomi. If you suspect you have a heart problem, though, speak to your doctor rather than buying an Apple Watch.

The Fitbit Versa 3 has built-in GPS. But, if you're considering saving more money by going for the Versa 2, be aware that the older model doesn't have it, rather surprisingly considering Fitbit's focus on fitness.

DZ09 Smartwatch Specs and Features

Want an Apple Watch after all? Read our review of the Apple Watch Series 6. And our guide to Apple Watches compared drills down further into the differences between the Apple models. And it has a few quirks: for example, you can use it to record VO2 max measured elsewhere, while many other smartwatches now, even cheap ones, are designed to calculate it for you. You can also use it as a dashboard to record ECG (electrocardiogram) readings, but we're not really sure why you'd want to.

The Xiaomi Mi Watch Lite is compatible with Android and iOS. As we said before, Apple Watches only work with iPhones. As you can see from the picture above, the Oppo also looks remarkably similar to the Apple, with its rounded rectangle shape. It's the first smartwatch from Chinese company Oppo and comes in two sizes: 41mm and 46mm.