Best smartphones to look forward to in 2015

With the pace of smartphone evolution moving so fast, there's always something waiting in the wings. No sooner have you spied the latest handset, then there's anticipation of something else, the next big thing to envy.

We've rounded up the best smartphones for 2015, those we consider to be the best across all platforms, and we've regularly updated that list as the smartphone world has evolved.

You can find those in our Best smartphones 2015: The best phones available to buy today feature.

Here we're looking at those phones that haven't yet launched, those we know are coming, or are anticipated. As we move past Mobile World Congress 2015, we enter the busiest time of the year for smartphone launches with those announced at the show appearing on shelves, and others following closely behind.

We'll be updating this list on a regular basis, with those device rumours we think are credible and exciting, and devices just announced but yet to hit the shelves.

LG G4

LG Display has confirmed the LG G4 will sport a 5.5-inch QHD LCD display, meaning the new device will offer a pixel density of 538ppi. The company has said the new display will deliver a "Quantum Jump in Colour Gamut and Brightness", along with improved touch sensitivity and richer, more accurate colours.

LG has also confirmed a new user interface for the LG G4, ahead of its announcement on 28 April. The device will come with UX 4.0 layered over the top of Android 5.0 Lollipop and the new interface will introduce several proprietary features. Quick Shot will allow you to take a picture with a double tap of the volume button on the rear without having to turn the display on first and the camera will offer three users modes including Simple, Basic and Manual.

Other rumours have suggested the LG G4 will be slightly curved, though not as curved as the G Flex 2, and it will apparently come with a 16-megapixel rear snapper. We do know from an official teaser video that we can expect a f/1.8 aperture so night shooting with LG's new flagship should be good.

There's rumours of a 64-bit hexa-core Qualcomm Snapdragon 808 chipset, so while it might not have the power of some rivals, it might offer better battery life and could be much more agressively priced.

But we do know that there will be a leather option for the cover, like the Moto X.

READ MORE LG G4: What's the story so far?

HTC One M9+

There were rumours of the HTC One M9+ before the M9 launched. This phone is now official, following a launch event in China. It's pitched at the Chinese market first and there's no word whether it will ever be seen outside Asia.

The HTC One M9+ has a 5.2-inch Quad HD display and is powered by an octo-core MediaTek chipset, has a fingerprint scanner on the front, as well as offering a 20-megapixel Duo Camera on the rear.

In some ways it's more progressive than the M9 flagship that was launched recently, with HTC looking to other hardware manufacturers, experimenting with that camera, but still offering high quality construction.

We're hoping it ventures outside of Asia, it certainly move things on for HTC.

READ MORE HTC One M9 Plus vs HTC One M9: What's the difference?

Huawei P8

Huawei's new 2015 flagship is the Huawei P8. It offers slick design with a high-quality metal body that's only 6.4mm thick, so it's thinner than the iPhone.

There's a Kirin 930 octo-core chipset inside and a 5.2-inch Quad HD display on the front, which is capable of generating some fantastic colours. 

However, Huawei has heavily customised every aspect of Android using its Emotion UI and some might feel that the heavy addition of features, and the departure from Android norms has gone a little too far.

However, the camera is making great claims, as it the battery management. The other exciting thing is the price: you should be able to get this flagship for around £100 less than it's rivals.

READ MORE Huawei P8: Metal meets Android modifications

Microsoft Lumia 640 XL

This 5.7-inch Lumia gives you a big screen Windows Phone experience, but really isn't that expensive. That's not uncommon for Windows devices recently, with the Lumia 640 XL available from €189, which sounds like a bargain.

It isn't the most powerful Windows Phone available, but there's some intesting details, like the 13-megapixel camera on the rear with Zeiss optics. There's also a 5-megapixel camera on the front, making it more appealing than the regular Lumia 640 it launched alongside.

In the hand it feels pretty good and although big, we think it's just about managable. The design is typical of Microsoft Devices in the post-Nokia era, and although it's plastic, it feel solid enough.

The 640 XL was launched alongside plenty of talk about Windows 10, but it's running Windows Phone 8.1 with Lumia Denim. It was slick and fast enough in our demo, but there's no telling what the real-world performance will be like.

READ MORE Microsoft Lumia 640 XL: Big brute packs in Zeiss lens (hands-on)

HTC One E9

We're sure that HTC has a number of devices lined up, one of which has recently surfaced as the HTC One E9. The name is a little odd, as the plastic body would suggest that it's actually the Desire E9 - following the Desire E8 we saw last year.

However, it's said to be a 5.5-inch device with a Quad HD display and MediaTek innards, rather than Qualcomm. This is likely to be a cost saving measure.

There's claimed to be a 20-megapixel camera on the rear and either a 13-megapixel camera on the front (like Desire Eye) or UltraPixel (like One M9).

It should be running Sense 7.0 and Android 5.0 Lollipop, but we suspect this will be a phone heading for China and not for wider international release.

READ MORE HTC One E9 surfaces

Sony Xperia Z4

Of all the devices forthcoming, least is known about Sony's plans for the Sony Xperia Z4. Sony didn't have an event at MWC 2015, meaning it skipped out of its previous hardware cycle. The next big event would be IFA in Berlin at the beginning of September, but this would give HTC, Samsung and LG almost six months before Sony's updated flagship arrives so we wouldn't be surprised to see the Xperia Z4 sometime during the summer instead. Recent rumours have suggested the speculated Xperia Z4 may actually be the Xperia Z3 Neo however. 

There isn't a huge amount to go on at the moment, but it's suggested that we'll see a slightly new face on the Z4 with a repositioning of the front-facing speakers, and perhaps a step up to Quad HD resolution for the display. It's been suggested that the casing will be exactly the same, rather than there being a redesign, which would support the claimed Xperia Z3 Neo name. With the M4 Aqua ditching the port-covered Micro-USB port, we'd expect the same in the next Xperia Z device.

Rumours suggest an updated camera too, still with 20.7-megapixels and optical image stabilisation on the back but a curved rear sensor and two more lens elements for collecting more light have been claimed. A boosted front camera is likely too, as is Android 5.0 Lollipop. 

There's no date on the Sony Xperia Z4 release at the moment, but with MWC out of the way, we suspect Sony will let things settle, before announcing it's next superphone later in 2015.

READ MORE Sony Xperia Z4 rumours

Sony Xperia Z4 Compact and Ultra

The Sony Xperia Z4 Compact is apparently going to arrive with 3GB of RAM, a 20.7-megapixel camera, 32GB storage, and a 4.7-inch screen with 1080p resolution. You can also expect a 3,000mAh battery, Cat 9 LTE, wireless charging and IP68 water and dust proofing.

The Sony Xperia Z4 Ultra should arrive with a 6.44-inch display with a QHD resolution. It should also come with 3GB of RAM but a smaller 16-megapixel camera and larger 4,000mAh battery. Unlike previous versions of the Ultra this model should also come with a stylus.

Sony has made a start on the Z4 family with a new 10-inch tablet, but there's been no sign of any phones just yet.

READ MORE Sony Xperia Z4 news

Asus ZenFone 2

Asus was one of the first companies to launch a new device in 2015 with the Asus ZenFone 2 launching at CES 2015 in Vegas.

The company stuck with Intel for the hardware, with an Intel Atom Z3580 paired with 4GB of RAM, which should make for a really powerful handset.

There's a 5.5-inch display, with 1920 x 1080 pixel resolution as well as a 13-megapixel camera on the rear. Asus is making great claims about this camera, saying it will offer low light performance like you haven't seen before but we'll be the judge of that when we get it in for review.

The ZenFone 2 has rear volume controls, like the LG G3, and it ships with Android 5.0 Lollipop skinned with Asus' Zen UI.

Fortunately, despite some premium specs, the ZenFone 2 comes with the $199 starting price tag. We're yet to hear exactly where it will be on sale, however.

READ MORE Asus ZenFone 2 preview

Asus ZenFone Zoom

We didn't see this one coming, until Asus teased "optical zoom" in an oh-so-obvious way. But Asus now has a smartphone with optical zoom that was announced at CES 2015.

There aren't many cameras with optical zoom around and the ZenFone Zoom is a world away from the Samsung Galaxy K Zoom. Samsung's model is more like a camera, however, with 10x optical zoom and a 20-megapixel sensor, along with Xenon flash. The Asus, however, is fairly slimline, cramming the 3x optical zoom 13-megapixel camera into a body that's still pretty slim.

To assist that camera is laser autofocusing, but we're yet to see if this all fuses together nicely, or if it's a mish-mash experience.

Elsewhere, the Asus ZenFone Zoom has a 5.5-inch display and will launch with Android 5.0 Lollipop, along with Zen UI. It's still some way off, however, with no word on when it might be available.

READ MORE Asus ZenFone Zoom eyes-on

Microsoft Lumia 1020 replacement/RM-1052

This rumour is a little on the loose side, but a leaked image appeared showing a Lumia model with a big camera bump on the rear. The Lumia 1020 was a mobile photography star, but has never been replaced and all of Microsoft's recent devices have been at the budget end of the spectrum.

There's a chance that you're looking at a new high-end PureView model, known as the RM-1052, but equally it could be a prototype of the cancelled Nokia McLaren.

But it's nice to dream that Microsoft Devices will fill the high-end with a 5-inch Windows 10 device with a great PureView camera.

We're not convinced by the bodywork, the metal and plastic fusion doesn't look like a finished consumer device, but it could be the birth of a new photography star for 2015.

Stephen Elop announced at MWC that a new flagship would be coming later in the year, so Windows 10 will have itself a new device to play on.

READ MORE Microsoft Devices news and reviews

Google Project Ara

Created by Motorola, and now shifted over to Google after the sale of Motorola to Lenovo, Project Ara isn't due until late 2015 but is essentially an exoskeleton that allows users to modify what parts they want. That way someone that wants to spend the bulk of their budget on the camera, but doesn't need as much storage, can chose to upgrade that way. Perhaps one person will skip NFC in favour of faster 802.11ac Wi-Fi, for example.

There should also be third party components on offer that will allow for competitive pricing as well as new types of parts - like sensors. A person with diabetes may want a blood sugar sensor where another may not.

Users can also looks forward to different textured options that they can 3D print off at home themselves. The speed this phone can develop at, without costing us as much, is very exciting indeed.

READ MORE Google's Project Ara modular smartphone: Everything you need to know