Kickstarter poster child Pebble was on hand at Google I/O this week — and while the smartwatch wasn't fully functional, a preview SDK for Android was made available, giving developers an early look at how the device and its e-paper display interacts with the operating system's intent messaging service. The information in the software development kit is still in its early stages and changes will likely happen before the actual product ships out this fall. If you're looking to get a head start on the most successful Kickstarter project to date, you can sign up to be on the official developer mailing list at the SDK's site.