Best Android phone ever?At first glance, Samsung’s Galaxy S7 looks almost unchanged from 2015’s S6. For several reasons, however, it’s actually a significant upgrade. Perhaps the most important is the microSD card slot, which lets you add up to 128GB for around £30 whenever you need to. The S7 runs Samsung’s TouchWiz version of Google’s Android 6 ‘Marshmallow’ operating system, which helpfully makes it easy to move your stuff to a microSD card.What else has changed?The main camera is reduced from 16 to 12 megapixels, which puts it on a par with the iPhone 6s camera. Samsung has decided to focus on capturing each pixel more accurately. It works: our photos looked highly detailed, correctly exposed and colour-balanced, while a change from widescreen to a squarer picture format helped to accommodate a wider range of scenes.The camera lens protrudes less now, but that’s because the case – available in black, white, silver or gold – is fatter than than the iPhone 6s, but its overly rounded edges make it nearly as tricky to hold. The glass back is more grippy than the iPhone’s aluminium, but shows fingerprints. Talking of which, the S7’s fingerprint reader unlocks the phone, but only after you’ve woken it by pressing a button. This isn’t as quick as the rear-mounted instant sensors on rivals such as the Google Nexus 6P.Performance was never a problem for the S6, and Samsung’s own Exynos 8890 eight-core processor ensures the S7 does most things almost instantly. It’s not the fastest for graphics, but we had no problems playing games. A Game Launcher mode lets you play without interruptions, which is a good idea.The ultra-sharp 5.1in screen remains excellent, covering 100 per cent of the sRGB colour range. Black pixels stay perfectly dark, and although brightness seems limited, it ramps up when you use the phone in sunlight. You can also show calendar and battery information while the phone is sleeping, without any noticeable power usage.The thicker case has room for a big battery, which lasted us just under 18 hours of video playback. This means you can stop worrying about keeping your phone charged, and when you do need to top up you can use a wireless charging point or plug in a fast mains charger to get to 50 per cent in just 10 minutes.As previously, Samsung has also launched an S7 Edge, with a display that wraps a little way around each side. Besides looking very stylish, this year’s Edge is also bigger, which, along with its higher price, really makes it a different product altogether. We’ll be testing it soon.VERDICTHaving fixed what was wrong with the S6, the S7 is probably the best Android phone you can buy.SPECIFICATIONS5.1in 2560×1440-pixel screen• 12-megapixel rear camera• 5-megapixel front camera• 32GB flash storage• microSD card slot• 802.11ac Wi-Fi• Bluetooth 4.2• 3G/4G• Android 6.0.1• 142x70x7.9mm (HxWxD)• 152g• One-year warranty.