Apple, is USB allowed now?

In the wake of the success of the Duet Display app, is using the USB connection in iOS allowed?

We are excited to see USB become available on iOS, but also hesitant to adopt it. We did submit an app that used USB a year ago and we got a call from Apple saying USB connectivity is not allowed. Our app also used PeerTalk, the same open source USB tech used by Duet Display.

Here is our full story

For the past year, we’ve been working on an app (launching early 2015) that turns your iPad into a graphic tablet for your Mac (like a Wacom tablet). Our app at its core also streams video content from the Mac to the iPad, so we were very interested in USB connectivity early on in our project.

We knew that using USB instead of Wifi was a decision we had to make early on, as it would completely change our direction of development. USB offers a reliable, low latency connection which is 100x better than any wireless technology (especially with Yosemite experiencing serious Wifi reliability issues).

We were also very hesitant to build a business around a decision Apple may change on a whim. So we submitted an app to test the waters, would Apple allow an app that requires USB? An Apple representative called us and informed us USB connectivity was not allowed

Even though our use of USB was rejected, we were determined to carry on. Our next best option was Wifi, but streaming high quality video with extremely low latency over Wifi is incredibly hard. To achieve the quality and responsiveness our app requires we’ve spent the past year building completely custom technology. We’ve developed our own network protocol that is designed for local wireless networks. We’ve built a custom video codec that is super low latency, very high quality and energy efficient. Our video codec is GPU accelerated and even partially written in ARM assembly (we are nuts).

This has been an amazing journey and we have a state of the art video streaming technology now. However if we had been able to go with USB from the beginning we would have shipped six months ago.

The developer behind Duet Display claims he spent 30 days building the app. This is quite amazing (although this controversy might reveal why) but 30 days is a reasonable risk to take on an App Store policy. For other developers out there trying to build innovative apps that require significant time investment, the App Store policies are just too uncertain . Unfortunately this uncertainty is stifling the potential of the iOS platform.


We’ve built an iPad app we call AstroPad that’s coming in early 2015.

Learn more