In January 2014, we released OmniGraphSketcher source code as the open source project GraphSketcher. You can download a build of the new Mac app from GitHub. We hope that the iPad app will make it back to the iTunes store soon.
We will, of course, continue to support customers who have already purchased the Mac and iPad editions of OmniGraphSketcher! To reach us, you can still select “Send Feedback” from the Help menu, email us directly at firstname.lastname@example.org, contact us on twitter at @OmniGS, or telephone us at 1-800-315-6664 or 1-206-523-4152.
We no longer sell or otherwise provide licenses for either the Mac or iPad editions of OmniGraphSketcher. If you previously purchased OmniGraphSketcher from omnigroup.com and need to download the most recent release, use this link. If you purchased OmniGraphSketcher from the iOS or OS X App Store, it should still be available for download via the Purchases section of the App Store application.