Duet Display, a screen-sharing app, enables you to use your iPad or iPhone as a second monitor. With a high refresh rate and easy setup, Duet Display can improve your productivity by capitalizing on your existing hardware.
Fast refresh: Duet Display has the fastest refresh rate of any screen-sharing app we've encountered. Movements are mostly lag-free, depending on your settings. Your tethered iPhone or iPad won't be as fast as a dedicated monitor, but they'll still be a joy to use.
Touch to increase productivity: Having more screen real estate allows you to multitask and accomplish more. Combined with the iPad's touch capability, you can work even more intuitively.
No network means security: Since Duet doesn't require a shared Wi-Fi connection, you can use it anywhere, provided you have a lightning-to-30-pin cable with you. That also means you don't need to worry about Wi-Fi snoopers when you're working at the coffee shop.
Customize to suit your usage: Duet offers different modes of operation to suit your system hardware and needs. Turn up frame rate, resolution, and performance settings for a more responsive screen, or tone it down if you're working on less intensive tasks.
High CPU usage: At higher settings, Duet Display can be taxing on your system. Even with the newer hardware, we've seen CPU activity jump from 10 percent to almost 80 percent. Keep this drawback in mind if you work with system-heavy tasks like video editing or image processing.
Supports only one device: There is no option to add a third display, even if you have the extra USB ports.
Trickle charge: With networked screen-sharing solutions, you can charge and share your screen at the same time. But since Duet relies on the USB connection to transfer data, your iPad won't be getting much of a charge.
Duet Display is an excellent screen-sharing app for those looking to make the most out of the hardware they already own. At the cost of high CPU load, Duet can provide almost lag-free responsiveness and a touch interface. With its tether solution, Duet allows you to take your work anywhere, even to places outside Wi-Fi range.