Relay is an iPad application that allows you to intuitively transfer tasks between your computer and your iPad. Whatever you're doing—reading webpages, listening to music, copying and pasting—Relay allows you transfer that in progress task to the other device so that you can continue working without interruption.

User Interaction

The UI metaphor we are currently using is that of flinging (or slinging? maybe throwing?). Fling items from the list in the iPad app towards the image of the computer to transfer that task to your computer. Fling a window towards one side of the screen on your computer to transfer the task being completed in that window to your iPad.

Some YouTube video demos of this interaction:

Transferring watching a YouTube video from a Mac to an iPad

Transferring a Google Map from a Mac to an iPad


The Mac client requires that "Enable access for assistive devices" is checked in the Universal Access System Preference Pane. Make sure to use the master branch if you want to see it work.

Project Particulars

At the moment there are clients for both Mac and Windows platforms. At the moment this repository should be considered very unstable but over the next few weeks the master branch should converge to a stable point. UPDATE. The master branch should now be slightly more stable and should actually work. Development will continue in the develop branch, with bigger increments to functionality merged over to the master branch every so often. For now the develop branch will be the best place to start from for adding functionality and fixing bugs.

Relay uses the HandOff library for describing and communicating information about tasks. The plan is to develop the HandOff library into a component that can be included in any iPad application so that application can send and receive tasks to and from the HandOff powered Relay client running on a computer. The HandOff library depends on Jens Alfke's MYNetwork library for network communication. That library implements a lightweight, BEEP like protocol called BLIP.

This project was started at the iPadDevCamp 2010 Hackathon. It was created by team Double Gravity, a collaboration of engineers from two companies: doubleTwist and Gravity Mobile.

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