Razer Kishi V2 vs. Backbone One vs. GameSir X2 vs. Gamevice Flex: Differences and Reviews 2025

Razer Kishi V2 for Android	Razer Kishi V2 for iPhone
US$99.99	US$99.99

Backbone One for Android	Backbone One for iPhone
US$99.99	US$99.99

GameSir X2 Type-C	GameSir X2 Bluetooth
US$69.99	US$59.99

Gamevice Flex for Android	Gamevice Flex for iPhone
US$99.95	US$99.95

Compatibility

Size: 92.2 mm x 180.7 mm x 33.9 mm

Weight: 123 g

iPhone	Android
iPhone SE (1st and 2nd) iPhone 6S/6S Plus iPhone 7 and 7 Plus iPhone X, 8 and 8 Plus iPhone XS, XS Max, XR iPhone 11 series iPhone 12 series iPhone 13 series iPhone 14 series	Samsung Galaxy S8 / S8+ / S9 / S9+ / S10 / S10+ / S20 Series / S21 Series / S22 Series Samsung Galaxy Note 8 / Note 9 / Note 10 / Note 10+ / Note 20 Series Razer Phone and Razer Phone 2 Google Pixel 2 / 3 / 4 / 5 / 6, and many other Android devices Max supported smartphone dimensions: 11.5 mm (thickness, including camera) x 170 mm (length)

Height: 3.70 inches (93.9mm)

Width (Contracted): 6.94 inches (176.2 mm)

Width (Extended): 10.14 inches (257.6 mm)

Depth: 1.28 inches(32.6 mm)

Weight:4.87 ounces (138.0 g)

iPhone	Android
All the iPhone series iPhone 14,14 Plus,14 Pro,14 Pro Max,13 Pro, and 13 Pro Max need a Adapter.	Fits all android phones in size

Maximum phone length: 173mm
iPhone / Android

iPhone / Android

Compatible with almost all mobile phones. The included Adapter Kit provides a wide range of Case and Phone Adapters to ensure the best fit for your phone. Utilizing these adapters will create a firm fit customized for your personal setup.

Software

The Kishi V2 has a free software app called Nexus – a dashboard that lets you launch games installed on your phone, spotlight other Kishi-compatible games, and is necessary to remap those two extra programmable buttons. The Nexus app also includes a feature that lets you seamlessly start a live stream on YouTube or Facebook.

Nexus is one of the worst parts of the Kishi V2, and most users often avoided it. Although the app allowed users to launch theri installed games easily, its inconsistent and sluggish performance made the software feel like it’s in early access. The images for installed games on Nexus are low-resolution and blurry, and the Nexus button on the controller did not work no matter how many times when pressed it.

The official Backbone app offers a slick, intuitive interface to genuinely make your smartphone feel like a console. Keeping all your Xbox (via Microsoft's streaming service), Google Stadia, and iOS titles next to each other streamlines your mobile gaming experience in a way that few other controllers replicate and all in gorgeous high quality. While game chat, groups, and screenshots aren't going to be the deciding factor for some, their smooth implementation is the cherry on top.

Backbone offers a reliable gaming hub and useful features like an in-app friend system that lets you add other Backbone users and set up voice chat rooms. The paid subscription service Backbone+ adds even more features, such as the option to connect an Android device using a Lightning-to-USB-C cable or capture gameplay at 1080p at 60FPS.

The GameSir X2 is one of the best phone controllers for both iOS and Android, from its tactile buttons and durable design to the included case and low price, it’s awesome value for money. But it’s missing audio jack, weird software support, and triggers with no travel keep it from taking the crown as *the* best.

On the Android side, it's just a simple companion app that lets you tweak the button layout depending on what you’re using. The reason is that the hardware buttons are in “Nintendo” layout (B at the bottom) rather than the “Xbox” layout (A at the bottom), which can lead to confusion for you and the games you’re playing.

For iOS, the app supports Bluetooth controllers only, so you’re out of luck in terms of any tweaking.

A big part of actually using the Gamevice Flex on a mobile app is using the software, Gamevice Live. This allows you to manage your games, and find new ones, and for finding new ones, it’s not bad.

Generally, however, users found the app to be a little buggy and poorly designed. It hasn’t been updated for newer iPhones — so some of the interface is hidden behind the Dynamic Island. It also failed to add games to the interface, which was an issue: you couldn’t figure out how to add Genshin Impact to the software. This meant you had to launch the game manually each time you wanted to play it.

The Backbone One app was best built and easiest to use, plus users encountered fewer bugs. The Backbone app provides a full suite to access your games, capture content and talk with other players. Of course, there is Backbone+, which gives you additional features like Twitch streaming and 15-second smart clip capture, done by buffering said video.

Design and Features

The Razer Kishi V2’s predecessor used a Joy-Con style controller that splits apart, the Kishi V2 opts for a Backbone-style extendable bridge design. This makes it much easier to fit a larger phone into the controller but is less portable than the collapsible design of the original Kishi. Nevertheless, sacrificing portability in favor of more compatibility is a good trade-off for most people – you’ll just likely want to invest in a travel case.

At just 123 grams, the Kishi V2 is lighter than both the original Kishi and the Backbone One. Hand fatigue is a common problem with portable gaming, so having a lighter device is a plus as it extends your gameplay session without worrying about hand cramping. The Kishi V2 ships with multiple adapters to help it fit a wide variety of phones.

The Kishi V2 features a standard A, B, X, and Y button layout on the top right. The buttons feel clicky and are enjoyable to press. The microswitches make a pleasant clicky sound that is not at all obnoxious, and pressing each button offers a nice little tactile bump that feels rewarding to press.

Four additional buttons are on the front of the controller: a Share button (for screenshots and gameplay recording), a Menu button, an Options Button, and a Razer Nexus button, which allows you to launch the free Razer Nexus app.

Source:razer.com

The Backbone One is aptly named due to its dog bone-shape. It features two independent sides of the controller, each roughly the size of a Nintendo Switch Joy-Con controller, held together by an expandable middle section. With a sliding and rigid backplate, you place your iPhone in its center, slotting the charging port into the Backbone One’s Lightning connector, giving traditional dual-stick-and-face-button control on either side of your horizontally-mounted smartphone. By using the Lightning connector, there’s no need to pair nor charge the Backbone One – your phone will recognise the controller automatically, while the Backbone will draw power from the phone itself. Power draw is minimal too – less than you’d see if you were using a cabled pair of headphones similarly using that Lightning port.

If you’re an Xbox gamer, you’ll be familiar with the button and stick layout here. Analogue sticks (complete with clickable buttons) are positioned asymmetrically, with face buttons in an A, B, X,Y configuration. You’ll also find a D-Pad below the left analogue stick, shoulder and trigger buttons, and a selection of menu, options and screenshot buttons, as well as an orange ‘Backbone’ button that jumps back to the accompanying app’s interface - more on that in a bit.

Ergonomically, the Backbone is comfortable to hold – albeit better suited for smaller hands. It’s extremely lightweight, weighing just 138g. It has a slightly bulbous base on each side of the controller that evenly distributes the weight and doesn’t make the unit feel top-heavy while playing. It also features a matte black finish with a slight sheen to it that unfortunately picks up a lot of fingerprints.There are two offset analog sticks in total, one on each side of the controller. They are smaller and a bit stiff, and the closest comparison I can make in terms of how they feel are the analog sticks on Joy-Con controllers. There’s a surprisingly good D-pad just below the left analog stick taking the shape of a rounded plus sign. It’s not clicky like everything else on the controller, but instead almost silent with a satisfying press.

Source:playbackbone.com

GameSir X2 with a full-sized back to the controller rather than a spine, like the Backbone One or Razer Kishi, gives it a more solid feeling in the hand too.

All the buttons have a satisfying, tactile click to them and the analogue sticks are fantastic to use: smooth and precise with plenty of room to travel. For comparison, the Backbone One buttons are just as clicky, but the sticks are a little shallower and have slightly less space to move. And when it comes to small design decisions, GameSir really shows it cares. From the rubberized grips round back and the included case for additional protection, to the connector freely moving up and down by 50 degrees, ensuring you don’t damage your port or plug. It also protrudes a little more, so chances are if your case doesn’t have a lip covering the bottom, you could use the GameSir X2 with the case on.

It’s a very thoughtfully designed piece of kit for gamers, barring one thing. The triggers don’t have any travel.

Source:gamesir.hk

The Gamevice Flex is the latest version of Gamevice’s mobile controller. Available for iOS and Android phones, it features a newly improved frame that proved to be more comfortable to hold. The Flex is lightweight – weighing 0.4lbs, it’s only slightly heavier than the previous model – and modest in size, with dimensions sitting at 5.6 x 4.0 x 1.3 in. The Flex’s thick textured plastic feels as durable as ever, and it still sports a USB Type-C passthrough charging port, making it possible to charge while using the controller.

The ridged thumbsticks better allow for precise movements when playing shooters, while the enhanced D-pad makes competing in fighters a real possibility. The larger Guide, Back, and Menu buttons are better positioned to make them more accessible during play. And the analog buttons that line the top of the Flex are staggered based on height, with the bumpers being slightly higher than the triggers, making it easier to distinguish between them.

An ergonomic form, tweaked button placement, redesigned triggers – all of these slight changes make the Gamevice Flex feel better to hold and use compared to its predecessor. Even better is the inclusion of a 3.5mm audio jack and the new Flex Adapter kit. The audio jack is a boon for anyone who has a smartphone that uses a USB Type C charging port. Previously, unless using Bluetooth, it would be impossible to listen to music or gameplay audio via a headset while also charging the phone. The Gamevice Flex bypasses this issue with the 3.5mm audio jack.

The Flex Adapter kit, meanwhile, was created to provide custom fits for phone cases. Most similar mobile gaming controllers struggle in this category; players will typically have to remove their phone cases before attaching the controller. The Flex kit mitigates this a bit by way of its Adapter Selector and 16 installable adapters. This is done by placing your phone within the selector’s grooves (indicating which adapters to pick) and then snapping them into each side of the Flex controller. Once placed, you should be able to snap the sides onto your phone without having to remove your case first. Removing them is just as easy.

Source:gamevice.com

Battery Life

Since the Razer Kishi V2 doesn't offer any internal batteries, existing as a hard-wired controller that is powered over your phone's USB-C connection, its performance is superb.

Same with Razer Kishi V2, the Backbone One does not have a battery. Backbone One draws minimal amounts of power from the phone. Its power consumption is imperceptibly low. The degree of Backbone One's power consumption is so trivial that you could leave Backbone One plugged into your phone overnight without any discernible change in your phone's battery life.

500 mAh Battery and Type-C Charging Port: GameSir X2 Bluetooth has a powerful long life 500 mAh battery which allows gamers to play games for about 20 hours under normal using. After 2 hours fully charging, GameSir X2 Bluetooth will be back as your most trusted partner in your every game.