The Blu Vivo Air is something of a paradox. This phone approaches the technical limit of how thin we can make a modern smartphone. It's not the absolute thinnest phone, no, that race is ongoing with successive manufacturers cutting their phones down fractions of a millimeter at a time to claim the latest title. But it is still very thin — thinner than any mainstream flagship device you'll find in your local carrier's store. The design evolution of cell phones has been a bit of an oddity. In the early years we were obsessed with making these devices smaller — 1996's Motorola StarTAC and 2004's Motorola RAZR V3 were revelatory designs. But since the 2007 arrival of the iPhone we've been trending in the opposite direction: bigger. These phones have gotten slimmer over time, sure, but the flagship devices from Samsung, HTC, LG, and even Apple are all now 5-inch-plus monsters. Verizon is offering the Pixel 4a for just $10/mo on new Unlimited lines But these flagship devices bring with them flagship specifications and flagship prices. The Blu Vivo Air charts an opposite course — it shoots for extreme thinness and surprising affordability. That comes at the expense of the specifications, though. There are engineering tradeoffs to be made in making a device this thin, but more significant might just be the tradeoffs made to get the phone down to this price. These are the key numbers you need to know: 5.15mm and $199.00. About this review We're writing this review after spending a few weeks with the Blu Vivo Air; our unit was provided to us by Blu. It's running Android 4.4.2 KitKat (build BLU_D980I-V08_GENERIC). During our time we tested the Vivo Air on AT&T's network in Cincinnati and Columbus, Ohio, and it was connected to a Moto 360 smartwatch throughout our review period. The Vivo Air is what's called a "white label" device, in that it's a rebadge of another manufacturer's device, in this case the Gionee Elife S5.1. This phone also exists as the Kazam Tornado 348, Allview X2 Soul Mini, and others. They all have identical hardware, though the software on each is completely different.

Blu Vivo Air hardware It's so thin If you asked us to sum up of the design of the Blu Vivo Air, we'd call it the love child of an iPhone 5 and a Sony Xperia Z2. The front and back are single sheets of glass, punctuated only by holes for the speakers and camera flash. The edge of the device is ringed with a gold-hued aluminum magnesium alloy band, a matte finish for the bulk of the short journey from front to back with polished chamfered edges. It's a slab of a device, with flat edges and slightly-rounded corners.

But let's just talk about how thin this phone is for a moment. Measured from the front to the back it's a mere 5.15mm thick. That's thinner than any flagship smartphone from the major manufacturers, even the vaunted iPhone 6. And it does this without a hump for the rear-facing camera, unlike the aforementioned iPhone (or the Samsung Galaxy S5, for that matter). As a measure of just how thin this phone is, take a look at the 3.5mm headphone jack on the bottom. It's offset, slightly closer to the back than the front. The capacitive back button is stacked directly over the headphone jack, pushing it down by a fraction and moving it off the front/back centerline. Amusingly, the sheath at the end of the headphones plug is actually thinner than the phone itself (also, the headphones are surprisingly good for being included with a $200 phone). Also on the bottom you'll find a dead-center Micro USB port and a pinhole for the microphone.

The left edge of the phone sports the power button and volume rocker, both slivers of metal that match the band around the phone with their own miniature chamfers. They offer a satisfying physical and auditory click to them, but also a disappointing degree of wiggle to the sides. For a phone with such a narrow profile we'd have expected tighter design tolerances. On the right is a SIM card tray, up top is nothing.

The back of our phone was an expanse of white (the phone is also available in black), punctuated only by two slits for the loudspeaker in the bottom right corner, a pinhole for the rear mic at top center, and the rear-facing camera and flash at the top left. The camera itself actually doesn't break the plane of the glass or even have its own lens segment — it's the camera flash that sticks through. The round LED module sports a chrome ring around it to stop the flash from spilling over into that single sheet of rear glass and into the camera. Apart from that, there's a simple gold BLU logo printed towards the bottom.

The front of the device is equally clean and spartan, if perhaps a little dated. It is, naturally, dominated by the Super AMOLED display, a 4.8-inch panel with a resolution of 720x1280. It's not the highest quality or densest display out there, but then again, this is a $200 phone we're talking about. Above the screen you'll find a black pill-shape for the proximity and ambient illumination sensors, a slit for the phone speaker, and the circular black hole of the front-facing camera, all in a neat little row. Below the screen one will find capacitive buttons to open menus, go home to the launcher, and go back. Yes, this is an old school layout, and it's a bit frustrating for those of us that would prefer on-screen buttons, but it's what we've got. For as thin as the Blu Vivo Air is, the components inside can only be made so small. There's a limit to today's manufacturing capabilities, to what Blu could afford to put in this phone at this price, and even to physics. So that means that for all of its thinness, the Vivo Air is not a "small" phone. It's kind of a pancake effect in play here — most of the same (kind) of chips, sensors, radios, and batteries had to fit inside the Vivo Air, but with less depth available. So in squeezing it from the front and back it spread out a bit to the top and bottom. The 5/8-inch bezels on the top and the bottom gave the manufacturer a place to put the cameras, speakers, ports, and buttons (none of which overlap with the display — there's that little space inside), and they also provide a nice visual balance to the front.

The screen itself was fairly solid, with AMOLED's signature deep blacks and vibrant hues, although unlike some other manufacturer's panels the Vivo Air's was fairly well balanced in not being too saturated. That said, the 720p resolution is not the greatest and we did notice the pixels every so often after years of using 1080p-equipped phones. More frustrating, though, was the brightness, or lack thereof. If you're indoors, the Vivo Air typically does alright for brightness. But as soon as it's in direct sunlight, it's game over.

While the outside is a generally solid story, what's inside the Blu Vivo Air is a bit of a different tale. And this is where the $200 price tag comes into play. Instead of a top-tier or even mid-range Qualcomm processor inside you'll find the MediaTek MT6592, an octa-core chip clocked at 1.7GHz. It's paired with an ARM Mali-450 GPU, 1GB of RAM, and 16GB of storage (with no microSD expansion to be had). There's a standard assortment of Bluetooth 4.0 and Wi-Fi 802.11n radios, but the cellular communications top off at HSPA+, and even that's limited to the 21Mbps version. Yeah, there's no LTE here. All of that combined makes for a phone that's actually fairly speedy. With fewer pixels to push around (the 720p screen's pixel count is less than half that of a 1080p screen, and one quarter of what you'd find in something like an LG G3), the Vivo Air actually manages to be rather responsive in general use. Whether it's scrolling in Chrome or even blasting around tracks in Real Racing 3, the Vivo Air held up admirably for what you would find inside. Sure, it was occasionally hit by a pause when opening an app and it wasn't the quickest to boot, but by and large the hardware held up to what the software and users asked of it. Even the lack of LTE wasn't consistently awful, though there were occasions it was kind of painful. Despite offering 21Mbps support, we rarely saw higher than 6-7Mbps in download speeds over AT&T.

Blu Vivo Air software Well, that's, uh … I don't know why that happened Typically when we review a phone we want to spend at a bare minimum a week using the device. We want to put it through the gauntlet and push it to the brink, yes, but we also want a chance to use it as a normal device. Putting a phone through a battery of tests isn't a good measure of what it's like actually using the phone, it doesn't give us time to discover its quirks and adapt as a real owner would.

The software that's on the Vivo Air feels … half baked. The one piece of software you'll interact with most frequently is the launcher, and it's an experience that's just plain weird. Sure, you hit the home button from anywhere in the phone and it drops you back to the launcher. But in contrast to the standard-since-the-dawn-of-time Android paradigm of a launcher with multiple pages on which you put apps and widgets coupled with an app drawer where all of your apps live, the Blu opted against the app drawer and instead drops all of your apps on the launcher screen. It's very much like an iPhone launcher in that regard, except that you can also intersperse widgets with your apps and place them wherever you like on the screen (so long as they're on the 4x4 grid). But it somehow feels less natural. The spacing seems too wide and the squaring off of all the icons — even round or non-square icons get a translucent white background — make everything blend together.

The software that's on the Vivo Air feels … half baked.

In an odd twist, however, Blu offers the option to change things up. Either hitting the menu button in the launcher or opening the oddly-named "Color" app gives you choices to customize the launcher. In here you'll find wallpaper options, sure, but also themes. The standard Vivo Air theme comes with the squared icons and stark colorful default wallpaper, while "The boat" (such apt naming here) rounds the icons off and swaps a bunch out for softer, bubblier designs and a boat background. And "Android" goes to the default Android icons for everything — it's a much more familiar visual experience.

The "Launcher3" (that'd be the launcher app's formal name) experience's weirdness continues to the multitasking view. It's triggered by holding down on the menu button, opening a side-scrolling card view of your open apps, which you can swipe off the top to close. It's very webOS/iOS in implementation. But frustratingly, you can only get to this multitasking view from the launcher itself. Holding down on the menu key when in any app merely opens the available menu, no matter how long you hold. Tap the home button and it drops you back to whatever you were last doing in the launcher — if you got to your current app from the multitasking view, you go back to multitasking view, meaning you'll have to tap the home button again to actually get to your list of apps. All of this launcher weirdness can be very easily overcome by simply downloading and using the Google Now Launcher, thankfully. It's an easy install from Google Play, and once set as your "Complete action using: Always" choice, there's nothing to worry about. You get Google Now a swipe away, you get a proper app drawer, and you even get the classic vertically-scrolling multitasking view when holding down the menu key from any app (and home will always take you back to the launcher). So there's that weirdness out of the way, let's talk about the lock screen and notifications. When it comes to lock screen security you have the option of a simple swipe up to unlock, pattern tracing, or a numeric PIN. Pretty standard fare here. A few notifications display on the lock screen, namely the number of missed calls and text messages received. But weirdly we've had Facebook notifications show up in a Facebook blue box in the center of the lock screen, and at other times unlocked to a Hangouts quick reply widget overlaid on the launcher.

There's absolutely no visual cue that this is something that can be done, but from that lock screen you can swipe in from the right to bring in what we'll call a "lock screen actions widget". It offers four options, each of varying usefulness and impressiveness: camera, record, flashlight, and fake call. Camera, the default choice when swiping over, immediately fires up the camera sensor (in a oddly-stretched square) which offers both tap-the-icon-to-shoot and tap-to-focus-and-shoot functionality, as well as a small button to launch into the full-fledged camera app. "REC" starts and audio recording until you tap again to stop, and "Torch" toggles the rear LED on and off.

The most intriguing option, though, would be "FakeCall". Tap it and in 15 seconds the phone will light up with an incoming call screen and ringtone as if, well, you've received a call. The default is an unknown caller, but you can also program in the name and phone number of somebody more important than whoever you're talking to (the boss if you're talking to your wife, or your wife if you're talking to your boss) to "interrupt" you with an excuse to get out. There's even a female voice that repeats "Hi, can you send me the file as soon as possible please?" so those nearby can hear that there's somebody on the other end of the phone. It's just up to you to act surprised and then serious and convincingly apologize "I need to take this, sorry, let's get lunch sometime" and then not actually get lunch sometime.

The notifications drawer is mostly stock Android, though toggling over to the settings side brings up a grid of circular buttons to toggle various settings. Below that's a screen brightness slider, while above is a widget showing how much of the phone's RAM is in use with a funny little vibrating cartoon rocket. It's not at all clear what it's supposed to do — tapping on it launches the rocket (yay for animations?) while clearing out a sliver of the unused RAM. At best we were only able to clear about 10% of the RAM using this, but that's completely ignoring that these sort of memory managers haven't been needed in Android for years (and that any RAM we "cleared" quickly filled back up within minutes as the apps). The behavior of the little toggles wasn't always clear or specific. For example, the "General" button with a speaker icon and "Meeting" with a phone bookended by squiggles are actually paired — they toggle between each other, going from "make noise" (General) to "just vibrate" (Meeting). Guest Mod(e) allows you to lock down the your communications history and photos if you're handing over your phone, while Quick Pow(er Saving) throttles down the processor speed to extend battery life.

It's as if there wasn't a unified design team building the software that was installed on this phone. Another interesting software touch would gesture unlocking (dubbed "quick operating") wherein you can trace a "c" on the dark display to unlock directly into the camera app, a "u" to launch into music, a backwards "c" into contacts, and an upside-down "u" into messaging. It's not immediately clear when you first check out these options, though, is that you can assign each gesture to open whatever app you want or to immediately dial a contact of your choice. There's also some touches borrowed from others — double tap the phone to wake, flip to silence an alarm, dial by lifting the phone to your face, answer by picking up the phone, and buzzing to remind notifications you missed while the phone was sitting there. The gesture launching worked flawlessly for us, though most of the others were hit-and-miss. And therein lies the biggest rub with the Blu Vivo Air's software: it's incredibly inconsistent. It's as if there wasn't a unified design team building the various components that were installed on this phone. Some things just don't seem fully thought through (that you can only get to multitasking from the launcher), others are catch you off guard and leave you scratching your head as to why that happened the way it did (only Facebook getting a lock screen notification, or the Hangouts quick reply overlay), and other still are neat features with considered designs (lock screen quick actions). It's just… bizarre.

Blu Vivo Air camera You get what you pay for On phones like the iPhone 6 and Galaxy S5, the camera lens juts out for a reason — having more space between the lens and the sensor means that the sensor can be larger, and thus collect more light, and therefore take better photos. With the Blu Vivo Air forgoing having such a hump, what you instead get is a camera with a tiny lens and a tiny sensor. It's stated to be an ƒ/2.4 aperture lens on the rear, but even that number can't be compared to the ƒ/2.2 lens on the Galaxy S5 or the iPhone. Those lenses have more than just a wider opening — they're simply larger and deeper.

At 8 megapixels the Vivo Air matches, at least on paper, what Apple brings to the table. But we've long argued that resolution isn't everything, in fact, it's a small part of the equation. It makes a difference when you want to zoom in on a photo, for example, but the physical size of the sensor and the physical diameter of the lens make a huge difference on the quality of the photo, as do buzzword terms like optical image stabilization (physically stabilizing the sensor against vibration) and backside illumination (changing how things are laid out to let more light get to the sensor pixels). The Vivo Air doesn't have these things. Nor should we expect such in a smartphone at this price. Photos taken by the Vivo Air aren't remarkable in any right — colors are muted, there's a lot of noise when things get dark, the shutter response is on the slow side and focusing is not what we would describe as "speedy." It'll do for utility shots, but you probably won't want to print and frame anything taken with this phone.

The Blu Vivo Air in real life Why's your pocket beeping? As mentioned earlier, we like to actually use phones in the process of reviewing them. So in toting around the Vivo Air for the past few weeks we've gotten a good feel for it and been able to acclimate to its oddities. Some we were able to get used to and even appreciate, like the lock screen quick actions. Others, like the multitasking behavior, left us scratching our heads. Sure, we could have switched to the Google Now Launcher and called it a day, but we wanted to use this phone as a normal person would use it. A normal person doesn't install a custom launcher or know that Android's been designed with on-screen buttons since Android 4.0 was released in 2011. So that meant living with some of the weirdness and trying to ignore the rest.

But, by and large, using the Vivo Air was like using any other Android phone (or even a Samsung Galaxy S4, if you're into menu keys). Most every app you'll interact with on a regular basis is its standard version from Google Play, the launcher doesn't have to look all goofy if you don't want it to, and there are some genuinely useful features at play here. Now, you might be wondering how much of a battery can get shoved into so thin a frame. A surprising 2100mAh cell is inside this slim package, which when combined with the somewhat dim 720p Super AMOLED display, low-speed multi-core processor, and lack of LTE meant that we were very easily able to get an entire day's use out of a single charge. Unplug the Vivo Air at 8 in the morning and it was still going strong by 9pm. Standby battery usage was also fantastic — there were several occasions where we neglected to plug the Vivo Air in overnight and the battery dropped just a few percentage points as those hours passed. More than once we forgot to charge the Vivo Air because we didn't notice its weight in our pockets when taking off our pants at night. We're not ashamed to admit that more than one of those "forgot to charge it" moments came in leaving the Vivo Air in a pants pocket because we didn't notice it still in there when disrobing for the night. In addition to being very thin, this phone is also very light — just 95g. And iPhone 6 weighs in at 129g, while the trusty HTC One M8 is a relatively portly 160g. The lightness of the Vivo Air is nearly as surprising as the thinness. We've held light phones before, but they were always these hollow-feeling plastic things. The Vivo Air manages to be metal and glass and yet still thin and light. It feels solid in the hand with its chamfered (but not sharp) edges and slab styling. This doesn't feel like a toy, and it certainly doesn't look like one. All of this is even more surprising given its low price tag. Sure, you pay for that with lesser internals than you'd get on a more expensive phone, but it still feels like, at least on the hardware front, you're getting more bang for your buck. There's just one glaring issue: this phone is not inherently stable. It's the sort of thing you only get to experience when you've used a device for an extended period, but the Blu Vivo Air randomly crashes, and crashes hard. It's turned on while just sitting on a desk and rebooted itself. It's been pulled from a pocket, only to be in safe mode.

The strangest misbehavior came when it apparently crashed while turned off in my pocket and booted into the automatic factory testing mode, which includes a test of the speaker emitting a high-pitched squeal for ten seconds, followed by testing the response of over various components like the accelerometer and proximity sensor (and presumably other tests before that), and then landing on a white-on-black menu to engage in more tests, clear the eMMC, check root status, and reboot. That's the sort of menu a normal user should never see. Heck, that's the sort of menu a power user should never see unless they deliberately trigger it. It's certainly not something that should randomly happen whilst stowed in a pocket. I'm an experienced user and seeing that kind of freaked me out (it brought back memories of my hopelessly-broken Galaxy Nexus), I can't imagine how a normal user would react to their phone displaying that kind of message and not responding to touch inputs. Blu says they're planning on releasing Android 5.0 Lollipop in June 2015 for the Vivo Air and several of their other devices. Hopefully they're taking the next few months to get their user experience straight and stamp out these discouraging stability issues.